BMW's 5 Series is both impressive and frustrating. We found the iDrive driver-interaction system tedious to use. Handling is agile and secure, and the ride is comfortable and quiet. The turbocharged engine in the 535i makes the sedan quick and returns a commendable 22 mpg overall, but the shifter is a bit complicated to use. The seats are very comfortable in the front and rear. Interior fit and finish is impressive. A V8 engine and the high-performance, V10-powered M5 sedan are also available. AWD is available only with the six-cylinder. Reliability has been average. IIHS side-crash results are disappointing.