This car is a blast to drive. It hugs the road, stays flat in tight turns, launches with gusto, and makes the driver feel like an integral part of the machine. (My car has a manual transmission, which helps with the last point.) A few downsides, but they all have to do with the fact that this is a small, sports coupe. Tiny back seat, limited trunk, and, although the ride is composed, it is active. About 21 or 22 mpg with my driving. The thought that the 135i is an entry level BMW is amusing. The 135i has the same engine, drivetrain, and suspension of the 335i, but it is 8.5" shorter and 400 lbs lighter. 300 horsies and 300 torquies in a short, light package with a great suspension. Fun car.
Owned lots of cars in my life, the 135i was one of them. The styling polarizes people, I really like it, but I can see why others don't like it. The performance is exceptional, and other than the run flat tires, rides pretty smoothly. Brakes are 6-piston brembos, and are phenomenal. Gas mileage is worse than indicated, and there are too many problems with the fuel system and the turbochargers in this car. The back seat is too small for anyone other than a toddler just heavy enough to not need any kind of booster seats. Consumer Reports ranks this as one of the best sports cars out there, sadly, with the worst reliability. If you intend to buy one, strongly consider an extended warranty, because parts and labor are extremely expensive for any BMW.
This is a car for anyone who would trade the convenience of four doors and the excess space of a larger car for an exhilarating ride and exceptional performance. The price of this car is really low compared to others with similar driving characteristics. In addition, the styling is somewhat unique, even within the BMW family, and you won't see 10 clones everytime you drive down a local street. Just don't expect a soft cushy ride, but do expect exceptional gas mileage when you travel in it. I am experiencing over 30 mpg on the highway in cruise-controlled mode at 70 mph, not bad for a turbo-charged 3-liter performance car. My mileage overall is in the 26 to 27 mpg range and performance is always only a tweak of the foot away.