Background: The bottom 10 inches of the LS 430 front door exterior is a plastic trim panel. It includes the chrome strip and everything underneath. The trim is attached to the door's structural steel with a combination of bolts, clips, and double-sided tape. The fasteners are held onto the trim with mounting tabs.

The trim extends below the structural steel, so it gets snagged easily on tall curbs. Trying to close the door when snagged will put a lot of force on trim-door connection. The weak point is the tabs that attach the fasteners to the trim. They appear to be joined with a weak plastic weld, which is the first thing to break.

This tutorial shows how to remove the trim, clean up old adhesive, adhere the tabs, and reattach.

Procedure:
Note: I picked up paint scratches on the panels while doing this. Use blankets instead of placing them on hard/dirty surfaces!

1. Remove the 4 nuts. All are 10mm. You will need a deep socket for the trailing-edge upper nut (upper-left nut in the pic).


2. The top row of clips appear to be locator pins. On my doors, they had no retaining force at all. The bottom clips detach on both sides fairly easily by pulling on the trim. Therefore, the main thing holding the door on at this point will be the adhesive.



3. Remove the tape with a long slender knife and a sawing motion. The big horizontal piece will be the main struggle. The diagram above is not quite accurate - the tape is more like 1/3 from the top instead of at the midpoint.


This is what it looks like underneath.



4. Use a 3M Stripe-Off Wheel to remove the tape from the door. It works very well.

(In this pic you can see I used black electrical tape to cover the clip holes. I was waiting on supplies, and they make a lot of noise when driving at freeway speeds.)


5. If the clips stay in the door, use pliers to pull them out. They will probably break. You could try to remove the door card and push them out from the inside, but the angle is very awkward and hard to get leverage. I did not bother and bought new clips instead.



6. For the tape stuck to the trim, the stripe-off wheel will grind away the soft plastic of the trim too, so I did not feel comfortable using it. Instead I soaked the tape in rubbing alcohol, scraped off what I could with a plastic interior trim tool, and repeated until it was gone. This was a lot of work and time. Maybe you can find a better way.


The culprit on both of my doors was the outer tabs that hold the threaded studs. None of the inner tabs holding the clips were damaged. You can see that a previous owner already tried to reattach them with some black hard adhesive (probably epoxy) but it failed.

This is because the trim is made from Polypropylene + EPDM + Talc 20%. It is a "low energy" plastic with good properties for automotive trim, but it is difficult to bond with standard adhesives. At the suggestion of user @LeX2K in this thread I purchased some Infinity Bond MMA 500, a 2-part adhesive designed for such plastics. You also need to buy an applicator and shipping is expensive. However, it works very well.


7. I prepped the surfaces by cleaning with isopropyl alcohol and water. Apparently MMA 500 does not require any surface prep like sanding. I used a lot of MMA 500 and placed heavy objects on top of the tabs to hold them down.


I probably used way too much MMA 500. It shrunk and left a weird-looking skin. Maybe this adhesive is only good for joining and cannot create new structure like epoxy can? Anyway, after curing for ~18 hours it was not completely hard but the bond was very strong, so I proceeded.



8. Buy new lower clips, part 75495-30030. This job is pretty labor-intensive, might as well replace anything that can get brittle while you're in there. Place the clips in the door first - the tabs on the trim allow the clips to slide on purpose, so it would be harder to line everything up if you placed the clips in the trim first.

I have aftermarket speakers in my doors that create a lot of vibration. The fit of the clips is loose, so I wrapped them in 2 turns of non-woven Tesa wire harness tape to prevent buzzing.



9. Clean the trim with alcohol, then replace the double-sided tape. I used 3M Super Strength Molding Tape, 7/8" width. One 5 foot roll was not quite enough for both doors, so I spaced out the long strip a bit. I think this is fine, the original strip seemed like overkill. However my tape was also a little thinner than the original. Try to find a longer roll of 1" thickness if you can.

You can also see in the pic above that I added MMA 500 to all the middle clips as well, even though they were not broken, as reinforcement. I sanded away the big blobs of MMA 500 on top of the outer clips because they were getting too thick for clearance.

10. Clean the door itself with alcohol. Finally, remove the red film on the 3M tape and reattach the trim. The top-row locator pins make it easy to get right. Push firmly on all the tape, it is a pressure activated adhesive. Replace all the nuts.

In my final result it looks like the trim is now a little bit concave at the trailing edge of the door compared to the leading edge of the rear door. I wonder if the factory double-sided tape was thicker?

edit: On the other side I added 3 layers of 3M tape and it was a little too thick 😭 2 layers should be perfect! You benefit from my trial and error

I will follow up to this thread in a year or two with an update on durability.