I bought the car used with relatively high-mileage. I was a little concern about the mileage but after I spoke to GM dealers, taxi drivers, my concern about the engine and drive train become less and less. It is a blast to drive. Handling is excellent plus with traction control you can't beat it. Excellent dash board layout head and tail lamp closed circuit monitoring for burnt light bulb.
I love this car when it is working, but I have had nothing but poblems with it from the start. I had to replace the tranny, get a new supercharger becuase the bearings went in the OEM, went through 2 alternators and 2 batteries prematurely, and it has several electrical gremlins. BUT! This is a great poor mans luxury/performance car as long as you don't get a lemon.
We bought the Bonneville to be used as our family car. This car has fit the bill very well. I was extremely pleased with the gas milage and overall comfort of this vehicle. After 9 years the thing drives like the day we purchased it. No complaints as of yet.