Great idea, I was hoping to buy a 348 in a couple of years...so would love to hear your experience with one!.
My only concern would be agreeing who repairs the car in extreme circumstances.
For example mate 2 goes out for a rag, comes back and the clutch has exploded. Mate 1/2/3/4 share the cost, or mate 2 pays the full cost?
Things like basic maintenance are much easier though
Also if you are all sharing the car, the car will probably put on many more miles than a single person who owns the car (as you will want to make the most of the time you have with the car), so take into account the additional depreciation.