I'm a bit disappointed with my 07 SI Sedan. I've had several problems with it. Tons and tons of interior rattles that can never be fixed, buzzing in the speakers, and now my 2nd gear is grinding like crazy. 2nd and 3rd gear issues are VERY common on these cars, and I'm now having trouble engaging 2nd gear at high RPMs, which is where the SI lives. The car is fun to drive, although it doesn't deliver what it should for its price. At almost 5k cheaper, you get the cobalt SS/ion redline with more performance. For a mere 1-2 thousand more, you get the mazdaspeed3/GTI which has a LOT more spunk and refinement to it. I would suggest checking out the Mazdaspeed3/gti before buying the Honda, sadly.
Place of controls in the interior, high revving engine, flat torque curve, great gas mileage (average 29-31), awesome seats, vtec, the sound of the stock exhaust (makes a beautiful sound)
New tranny, first and foremost. Too many people are experiencing 2nd and 3rd gear problems. New interior build - the quality is cheap and the plastic scratches easily. THICKER paint, more horsepower/torque to compete with the sports compact segment, BETTER headlights (very weak)