Interesting color. Do your homework on it. Have the paint examined, have the engine light read and know why it was triggered, have it mechanically inspected. Maybe it turns out legit. But, of it's at a BMW dealership and they won't CPO it, you need to ask yourself why that is. What do they know about it that is keeping them from fully backing that car.
A 328 is no slouch car. I've had an '07 328 xi, '08 M3, and '12 335 xdrive. Each is very different and was/am happy with all of them. Anyone who says you shouldn't hold your head up because you have a 328 is just being an ass and you shouldn't give their opinion any merit.
'08 Alpine white E92 M3 with DTC--Sold
'12 Alpine white E92 335 Xdrive with slush box
'07 Summit white Chevy 2500 HD Duramax/Allison
'12 Alpine white Z4 35is via EuroDelivery June 4th