Just because someone offered you good money for your car, does not mean you have to take them up on it. Are you not enjoying the 370?
I agree with the above that for just weekend fun, the Caymen, and more so the Beemer will bore you before long.
For a 28k weekend toy, there are many possibilities I think a Cobra would be near the top of my list I see Nobles are coming down in to that price range, you can also pick up some nice Fezza 348's and 308's for that money.