I have the 85-90 door ground f/x for my car. I had to repare them some with bondo but i was wondering if i had to add the flex agent into the paint for the ground f/x since they are fiberglass. Also the wing is fiber glass also do i have to add flex to it as well.

 

I just finished up a 1987 iroc-z and yes i did put flex agent in the ground effects, mostly for the front spoilers but since i did that, i went ahead and put it in rest of ground f/x. Cant tell any diff in looks of rest of car. good luck

 

I know with some lines of paint u don't have to add it.

 

didnt have to add it, just did just in case of any flexing .

 

From what I have learned with a lot of the newer paints you don't really need the flex additive because a lot of new paints flex enough. The only reason for the flex agent is for when your putting the parts on. I think its like something after 3 months it kinda dissapears.

 

I've noticed in alot of the more....Mainstream clears and enamels you don't have to add it. But the cheaper clears seem to require it still.

 

I use SEM flex.

 

Yea i just bought some Flexable filling puddy for my bumper from SEM. Ive never used their products before but im going to give it a shot.

 

I had the front gfx refinished when I added the Z hood and blisters to my sons car and we used a flex agent. I wouldn't dare not add it to the front at a minimum. I can't see where it would be necessary for the door gfx though.