No really, you're an asshole. Why would you circumvent the rules in something as pointless as AutoXing. The point is having fun not winning, you get nothing for winning, there's no incentive to cheat unless you're just a self absorbed asshole.
@ goldwar - I only know the rules for SM2 well, since that's where I was running my CRX, but in that class you were required to have a full interior, which would include the dash. Since Prepared is a class less modified than SM, I would say you cannot remove any interior pieces and this seems to be supported by the rules.
Also, E prepared is probably not the best place for you. Unless you have enough cars in that class (there are none in the club I race in) you're going to get bumped into a higher class running with DSP, where you'll have some serious competition. Even if you go all the way to SM2 (if you did an engine swap or something) you couldn't remove the dash, so I'd say no, do not remove the dash. I won't do you much good anyway. You need to have a full interior for almost all classes.