the ms3 is a very nice car, there really isn't anything out there better than this for the price of the ms3. Its a deal. There is no need for people to sell this car. If wanting something more economical, you'll certainly get something much slower. If speed is what you need, you'll end up getting bad mpg and a high price for a faster car.
The deal for the ms3 can't be beat, I dont know why people insist they have to sell theirs.
The op says he wants a 370z, nothing special, it will be faster, bug get less mpg and cost much more for insurance and car payment and you'll have much less room. What is the benefit of that decision besides a little more speed? Especially in this economy this seem like a horrible decision to make.
A 135 BMW was also mentioned. That is a nice car, tho repair costs on a BMW are ridiculous, and your car insurance as well as car payment will also go up. Once again why would you make this type of decision>
And the LS2 motor he mentioned, would result in worse mpg, probably higher car payment and car insurance.
I have no clue where people are getting the urge to sell their ms3, the price of it with the room and speed is the best it can be. Unless you've received a huge raise this year while most people didn't in this type of economy, it seems pointless to sell the ms3.