Never in my life have i seen bondo flex... it dries rigid and is extremely brittle. It's used mainly for aesthetics, and not for strengthening.

 

the amount of bondo/filler used will be so minimal it will look like a rock chip if it does chip. majority of the bumper will be fixed with fiberglass and resin the filler/bondo is just so the surface is smooth and wrinkle free...thin as a paper layer.

 

I had cracks on my Evo VII FB too. Someone back into me at the parking lot and the f*ker ran away Oh well.

Well I already fixed my bumper and it's ready to get primed and painted.
Here are the pics.








I could write a "How to Fiberglass Repair" if you guys want to.

Btw I did this on my Auto Body Shop Class.