Him enjoying the attention doesn't make the actions of the police right or just. He enjoys the attention, they are abusing their authority, Both things are true.

> they are abusing their authority

It's perfectly reasonable to question whether that vehicle is street legal when it passes by on the road. It would be my first thought. It looks like it's mounted on a boat trailer chassis, and the windshield appears to have questionable effectiveness at high speeds. Pulling him over to ask about it seems like they are doing their jobs. Especially when I am also a driver on the same road.

Is it legally reasonable? Does the local law make "that looks funny, might not be street legal" a primary traffic offense?