Take the money that you are going to lose by doing this trade and "upgrade" the components of the 325i you don't like. You are probally going to lose in the range of $5,000 and there is ALOT you can buy for the car with that kind of money (and your complaining about $700 for the trim..)
There are going to be alot of mods available for this car in the next year (probally including a turbo if your REALLY set on that). I also remember seeing someone putting together silver carbon fiber trim for the car (which IMHO would like ever better than the aluminum in the car). For more storage, you can replace the ashtray with a sunglass holder (there is a DIY on this site for it). You have alot of options... Sounds like you made a rash decision buying the 325 when you weren't completely sold on it... Don't make another rash decision that will in the end make things even worse..
FYI I did alittle work on this before I bought the car, based on previous model depreation, the "break even point" for a BMW is in the range of 30 months.. That's the point in which the car would be worth the same amount as what is left on the loan (assuming you didn't put anything more than the taxes down, and got a 5 year loan at a rate like 5%). If you get rid of the car before that point you will have to put money out of pocket to clear the loan.
E90 330xi Mystic Blue/Black Leather/Aluminum 6sp Manual ZSP/ZPP/ZCW/CA - Retired
F22 M235i Mineral Gray/Red Leather/Aluminum 6sp Manual ZPP/ZTP