Driving time for business trip considered working hours, and overtime??

[michguy1023]

Hello, I live and work in Michigan. I work for Company A, but contracted to Company B. So, i am a contract worker like most in automotive field.
I'm paid hourly, and CompA bills CompB for my hours.
I'm also currently paid a small amount per mile by CompB for my mileage between CompB office and our customers.

Comp B asked me to take a trip out of state, wasn't far... so I drove there.

I am paid by Comp B for my mileage.

I have 2 questions...

1) Should I also recieve hourly pay for my driving time? I'm assuming I will anyway.

2) more importantly, assuming they pay me for my hours of driving also, does that count towards my working hours? And am I entitled to overtime if I go over 40 hours including this said driving hours.

Thank you