You walk up to your RX in a parking lot and something looks off. The glossy black trim on the small rear quarter window, the fixed triangle of glass behind the rear door, is hanging loose. Or it is simply gone, lost somewhere on the highway.
If you drive a 2004 to 2009 RX330, RX350 or RX400h, this is one of the most common exterior complaints on this body style. Owners on ClubLexus, the Lexus Owners Club and CarComplaints have been reporting it for years. The good news is that it is a straightforward fix you can do in your driveway, as long as you prep the glass properly.
Symptoms You’ll Notice
Most owners notice one of these first:
- The front or top edge of the trim lifts away from the glass and you can slide a fingernail under it.
- You hear a flutter or light whistle from the back of the vehicle at highway speed.
- The trim is completely missing and you can see a strip of old gray or black adhesive on the glass.
- The trim is still attached but faded, chalky or cracked compared to the other side.
A lifting edge usually turns into a missing piece. Once air gets under the front edge at speed, it acts like a small wing and peels the rest off.
Why It Happens
This trim does not snap onto clips. On the 2004 to 2009 RX, the decorative piece is bonded to the outside of the quarter glass with adhesive tape. Owners who have talked with glass techs on ClubLexus describe it the same way: the trim is only held on by tape.
That tape spends 15 or more years in sun, heat, cold, car washes and road grime. The adhesive slowly loses its grip, usually starting at the leading edge where the wind hits it first. Complaints on CarComplaints for the 2005 RX330 show the failure happening anywhere from about 58,000 to 125,000 miles, so it is age and exposure, not a single bad batch.
Here is the part that frustrates owners. Lexus does not sell the trim by itself. In the parts catalog it is part of the complete quarter window assembly: 62710-48170 for the right side and 62720-48230 for the left side (dark gray glass). Owners on CarComplaints report dealer quotes of roughly $250 to $380 because the dealer replaces the whole window, not just the trim.
How to Diagnose What You Have
Before you buy anything, take two minutes and check these points:
- Is the trim loose or missing? If it is still on the car and not cracked, you may be able to clean and re-tape it. If it is missing, cracked, warped or badly faded, replace it.
- Is the glass itself solid? Push gently on the glass. It should not move. The trim is cosmetic, but the glass is bonded to the body separately. If the glass shifts, or you find water in the cargo area, that is a different problem (see the section on when to see a shop).
- Check the glass for chips or cracks near the edge where the trim sits. New trim will not hide a crack for long.
- Confirm the side. Left is the driver side on US vehicles. When you stand behind the vehicle looking forward, the right side trim is on your right.
- Look at the other side. If one side fell off, the other one is the same age. Press on its front edge. If it lifts, plan on doing both.
Tools and Supplies
You do not need special Lexus tools for this job. Gather:
- Plastic razor blades and a holder
- Adhesive remover (a product made for automotive trim adhesive)
- Isopropyl alcohol and several clean, lint-free microfiber towels
- Adhesion promoter wipes, if your tape maker recommends them
- Automotive double-sided acrylic foam tape (3M VHB is the one most often recommended on the Lexus Owners Club forum), unless your replacement trim already has tape applied
- Blue painter’s tape
- A hair dryer or a heat gun on its lowest setting
- Nitrile gloves, so skin oil stays off the glass
Step-by-Step Repair
1. Remove what is left of the old trim
If the old piece is still hanging on, warm it with a hair dryer for a minute or two. Then work a plastic blade under the edge and peel it off slowly. Don’t pry against the paint or the door weatherstrip.
2. Strip the old adhesive off the glass
This step takes the longest and matters the most. Warm the old tape residue, then scrape it with a plastic blade held low and flat. Follow with adhesive remover and let it soak for a minute before wiping. Keep going until the glass feels completely smooth under your fingertip. Any leftover foam or gummy spots will stop the new tape from sitting flat.
3. Clean the bonding area
Adhesive remover leaves an oily film, so it has to come off. Wipe the area with isopropyl alcohol on a clean towel. Then do it again with a fresh towel. Let it dry fully. From here on, don’t touch the bonding area with bare hands.
4. Dry fit and mark the position
Hold the new trim in place without removing the tape liner. Check that it follows the edge of the glass and the body line. Open and close the rear door to confirm the trim does not touch the door or its weatherstrip. When it sits right, put small pieces of painter’s tape on the body and glass at the corners as alignment marks.
5. Prep the tape
If your trim came with tape already applied, leave the liner on for now. If you are applying your own tape, run it along the back of the trim, set in slightly from the edges so it does not show. If you are using adhesion promoter, apply a thin coat to the glass where the tape will land and let it flash off per the label.
6. Watch the temperature
3M’s guidance for VHB tape calls for application between about 70°F and 100°F, and it is not recommended below 50°F. On a cool day, work in a garage or warm the glass and the trim with a hair dryer until they feel warm to the touch.
7. Set it and press hard
Peel back a short section of the liner at the front edge, line up with your marks, and tack the front end down first. Pull the rest of the liner out while you lower the trim onto the glass. Then press firmly along the entire length with your thumbs or a clean roller. With this type of tape, pressure is what creates the bond, so a quick tap isn’t enough.
8. Let it cure
Run painter’s tape across the trim to hold it tight. 3M rates VHB bonds at about 90% strength after 24 hours and full strength after about 72 hours at room temperature. Skip the car wash and pressure washer for at least three days.
Common Mistakes
- Leaving old adhesive behind. It is the number one reason re-taped trim comes off again.
- Skipping the alcohol wipe. Adhesive remover and fingerprints leave films that tape will not stick to.
- Using silicone or general-purpose glue. Silicone leaves a residue that makes any future bond harder, and hardened glue is a pain to remove later.
- Installing in the cold. Cold tape barely grabs. It may look fine in the driveway and then lift the first time you hit the highway.
- Not checking door clearance. One aftermarket buyer reported a trim that was long enough on the wide end to contact the door weatherstrip, which makes it easy to catch and break. Always dry fit with the door opening and closing.
- Ordering the wrong side. Double check left or right before you order.
When to See a Shop
Take it to an auto glass shop or your dealer if:
- The quarter glass is cracked or chipped near the edge.
- The glass moves when you push on it, or you find water in the cargo area after rain.
- You see rust or damaged paint on the body flange around the glass.
Those are glass and sealing problems, not trim problems. Replacing the glass means cutting out the urethane and resetting it, which is a job for a glass tech with the right tools.
Replacing the Trim Without Buying a Whole Window
If your glass is fine and only the trim is lost or damaged, you do not need a $170+ window assembly. At TheProAuto we make a rear quarter window trim replacement for the 2004-2009 Lexus RX330, RX350 and RX400h in UV-resistant ABS, sold as left, right or a pair. Follow the prep steps above and it goes on in an afternoon.
FAQ
Can I buy just the rear quarter window trim from Lexus?
No. Lexus lists the trim as part of the quarter window assembly (62710-48170 right, 62720-48230 left), so the dealer route means buying and installing the whole window. An aftermarket trim piece lets you replace only the part that failed.
Is it safe to drive with the trim missing?
The trim is cosmetic, so the car is safe to drive as long as the glass itself is solid and not leaking. The exposed adhesive will collect dirt, though, which makes cleanup harder the longer you wait.
Will this trim fit my 1999 to 2003 RX300?
No. The RX300 is the first generation body with different quarter glass. This repair and our trim fit the second generation 2004 to 2009 RX330, RX350 and RX400h.