Different inspectors can miss different things, and some are tougher to deal with than others.
My dual sported WR450 didn't have DOT legal tires or a front brake light sensor. The first place I took it was a motorcycle dealer and they couldn't let the tires pass, but could overlook the brake.
So, I took it to a small car mechanic which also inspects motorcycles. He wasn't as familiar with bike laws and didn't notice the tires. I doubt many car shops would question a plastic fuel tank.