Easiest thing to do first would probably be some evosport pulleys. here's the link
http://www.evosport.com/product/perf/perf_mercedes.html The 430's a pretty quick car but you have to remember you are gettting alot of weight rolling with a slow automatic tranny. Its not going to feel as quick of the line as a lighter car might, but you have to get past 0-60 times. This evosport setup should help you on the low end, but Mercs are not made for street racing. Go out on a highway and have some real fun, or better yet, put some koni's on there with Renntech springs and go find a curvy road. As for wheels, you have tons of choices and its really just personal opinon and finances. As far as agressive looks go, the AMG kit is pretty agressive IMO, but maybe go with a lorinser front bumper or something. My fav. exhaust setup for MB is eisenmann, they're sold thru a supplier called eisenhaus, google for their website. MB tuning is WORLDS different from honda tuning, but i think its more fun. Good luck.