How to fix a cracked Miata rear finish panel in 12 easy steps | Garage Rescue Miata

David S.
Update by David S. Wallens to the Mazda Miata project car
Jun 29, 2021

Things break.

And when talking about early Miatas, those things that break often include the rear finish panel found between the taillights. When we woke our NA Miata from its slumber, we found that the panel had cracked

Doh!

Two choices here. Well, three.

  1. Fix the panel.
  2. Replace the panel.
  3. Live with the panel.

Okay, how about a fourth, maybe: Cover the crack with a sticker?

[How to repair plastic trim.]

We went with No. 2 because we're thrifty and clean.

Step 1: Be pissed because some brittle plastic broke and now you have ot fix it.
Step 2: Go back and fix the typo made in Step 1.
Step 3: Realize that it could be worse.

Step 4: Pick up some two-part epoxy from your favorite hardware store because the stuff you have on the shelf had solidified into a solid block.
Step 5: Plan ahead and grab something to use as a splint. We went with some bamboo skewers.

Step 6: After removing the taillights, pull the rear filler panel. (And while you're there, maybe clean up things, too.)
Step 7: Rough up the back side of the repair area with some steel wool.
Step 8: Realize that you’re kinda approaching the home stretch.

Step 9: Tape the pieces of the filler panel in place, stabilizing the repair with your splint(s). Use some painters tape to keep the epoxy off the front of the panel.

Step 10: Taking care to not get the epoxy in your hair, eyes, mouth, etc., slather that stuff all over the backside of the break. Coat your splints, too, as they’re not leaving your car. Don’t forget appropriate eye, hand and ear protection.
Step 11: Allow everything to dry.
Step 12: Remove tape from the front of the panel and prepare to reinstall. (Now that the piece is stable, we can properly clean the exterior, too.)

Of course, you could still slap a sticker or two over it. 

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Comments
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captdownshift (Forum Supporter)
captdownshift (Forum Supporter) GRM+ Memberand UltimaDork
6/29/21 12:43 p.m.

I've never used splints before and now I feel like a moron for having not done so as it HAS to simply make things easier and ensures a better fitting end result with less flex and strain placed upon thr repair or thr brittle surround. 

 

Thanks for the game changer. Well worth the price of admission. 

David S. Wallens
David S. Wallens Editorial Director
6/29/21 1:16 p.m.

Thanks. Yeah, just two bamboo skewers grabbed from the kitchen. 

WonkoTheSane
WonkoTheSane GRM+ Memberand SuperDork
6/29/21 2:26 p.m.

The question is, did you REALLY choose #2 because you're thrifty and clean, or did you mean cheap? :)

David S. Wallens
David S. Wallens Editorial Director
6/29/21 3:05 p.m.

In reply to WonkoTheSane :

Boy Scout motto, right? 

WonkoTheSane
WonkoTheSane GRM+ Memberand SuperDork
6/29/21 3:08 p.m.
David S. Wallens said:

In reply to WonkoTheSane :

Boy Scout motto, right? 

Sure :)

I get it, it's hard to type when you've bonded 3 of your fingers together with plastic weld ;)

David S. Wallens
David S. Wallens Editorial Director
6/29/21 3:11 p.m.
WonkoTheSane said:
David S. Wallens said:

In reply to WonkoTheSane :

Boy Scout motto, right? 

Sure :)

I get it, it's hard to type when you've bonded 3 of your fingers together with plastic weld ;)

I was totally amazed that didn't happen. And I was taking photos, too--no glue on the camera, either. I'm shocked as well. 

calteg
calteg Dork
6/29/21 3:15 p.m.

I must have incredible luck. I've owned 9 miatas, 7 or those were NA or NB. Never had a single damaged rear finish panel.

David S. Wallens
David S. Wallens Editorial Director
6/29/21 3:17 p.m.

I think this one broke while the car was parked. It was parked with the rear end up against a wall, so it's not like anything hit it. I can't remember the panel being broken before I parked the car. 

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