2006 BMW 5 Series 525xi 4dr Sedan AWD (3.0L 6cyl 6M)
Overall a great car. Smooth ride, quiet and comfortable. The engine in the 525 seems underpowered for the vehicle size which causes the transmission to shift strangely in gears 1 and 2. Very little road noise, great handling and gas mileage. Contrary to many comments the iDrive is not that difficult to learn.
Exterior styling. Mileage.
More engine horsepower. The 06 525 has 225 horses but still not enough for the cost. 300 hp should be a minimum. Go for the 550 if you can afford it. If not, the 530 gives better performance. Driver and passenger drink holders are a joke.