I have to disagree with you on that. My car is tuned for SQ competitions, and I have been scoring between 280 and 310 in all 6 comps I have been in. Took first place in all of them. ANd in 4 of those events, I ran SPL as well with the car tuned for SQ, and have hit between 145 and 147 in each of those. Whoever said it is all about the amount of money you are willing to spend is dead on. The entire car was dynamatted when the panels were removed to paint them, and the doors were completely sealed up with dynamat and a little bit of duraglass in places we couldn't get the dynamat. The trunk was carpeting was completely removed and dynamatted as well. I am also running a set of $1,000 component speakers on a $600 amp, and for subs I am running 2 $500 subs on a $1000 amp. The box was also professionally built by one of the instructors at the Installer Institute in FL. Not trying to bring up how expensive my stereo was, just saying that if you're willing to spend the cash that it takes, you can compete in sound comps with our cars.Honestly I don't know how our cars would hold up in a sound comp. The horrible acoustics just kill us and anyone with a cavalier or something of the sort would basically just bend us over. I have 2 12" Kicker L7's and I've been almost matched by a cavalier with alpine type-e's its bad...real bad.
I was thinking the same thing cause mine didn't really rattle that much either before I dynamatted itI would get your car checked then. I mean, even before I dynamatted the entire car and put the custom box in, I was running with the same 2 12s in a dual ported MDF Carpeted Box. Nothing but the lisence plate rattled. I hate to say it, but maybe your car rattles like that just because. Try the weather stripping though. It does work. Also, have you tuned your amp properly? I had a friend complain about the same thing, but it was because his amp was tuned incorrectly.