Before I bought my 03, it had gotten a new tranny. The lower plastic engine cover wasn't put back properly and it wasn't long before a plastic retainer or two wound up missing, and the thing drooped a bit. My car went in for brake work recently, and it wasn't until I opened up my trunk and saw the engine cover sitting there that I realized the dealer removed it.

I'm currently running around without it; is there a big difference for things like intercooler air flow? I'm debating as to round up the parts to put it back in. I only have about 2-3 of the original retainers.

 

Bump.

 

I don't have mine on and either do about 7 kids I know with evos. I don't think I would take the time to put it back on. If you are planning on taking your bumper off every again then I would leave it off cause it is just a extra ten minutes in clips to pull out. Also you said the dealer ship took it off so that also tells you something right there.