I had one before I got the 135. If you're ok with getting about 170 miles on a tank and having the car drink a liter of oil every 2-3k miles, then it's a really fun car. It pulls like a freight train at higher speeds. I'd be sure to either get an extended or third party warranty and make sure it covers the SMG (including the clutch). If the SMG goes kaput, you're looking at a minimum of $5k in repairs.
'11.5 ///M3 | SSII/Fox Red | ZCP | DCT
'09 135 | AW/Black | 6MT - Gone
'06 ///M5 | IB/Black | SMG - Gone
'98 ///M3 | TiAg/Dove Gray | 5MT - Gone
'07 ///M Coupe | IB/Black | 6MT - Gone