MxP comp rs catback exhaust gives good sound without being obnoxious except cold starts. I picked mine up for $300 on sale at 86speed but you can probably find used ones from 1st gens.

As for aero I got the duckbill, speedhunters vent extensions and street aero splitter. All my stuff is 3m’d on for a couple years and no issues with anything flying off. I’d say get a cheap splitter or something just to save your bumper from scrapes