the plywood I think is 1/2? but this was to replace the undertray. I will use that later as a template for the front splitter. There are other materials similar to alumalite, sibond, alumacorr, all go for about same price of about $100ish per 4x8 panel or so.
The only small issue is to space out the splitter down about 1/4" or so since the Stillen has that step down lip u can see on the pics below.
