Attention Lawyers and Cops!!! Answer Please!!!!?

My fiance got pulled over , on his b.day no less , for "having an obstructed view" ( 2 tree air fresheners on rear view mirror). Subsequently , they popped him for DUI. He was 2 houses away from ours. Do you think that was a legitimate reason to be pulled over? He wasn't speeding or swerving or driving erratic, we think the cop just targeted him b/c it was 3am.