Find and drive a car with ZTR and 18" 398 wheels (the ones that come with non-RFT tires). Become amazed by the fact that you have found an F30 that feels the way older 3 series used to.
Ignore M Sport if you don't care about the looks.
Sport seats with tight side bolsters + sensatec = sweaty back all day long.
This
http://www.bmwusa.com/Standard/Conte...?CMId=d6oqvx9n comes to $48,570 including d&h, which should be an easy thing to negotiate below $45K.