Evening chaps, when i start my audi a3 it makes a grinding worn sound like a rusty wheel. After driving a little the sound goes away. any ideas??

Sounds like the starter may be hanging up on the fly wheel.

Sounds like the starter is not disengaging from the flywheel.

sounds like the fanbelt slipping as they warm up they get sticky and stop slipping so much-normally happens on cold mornings.

I am guessing this is not your every day driver???? It is surface rust on the brake rotors, once you press the pedal enough the rust is cleaned off and no more noise.

A rusty wheel passed me recently could it have been yours and does this explain the grinding worn sound going away?

Could be a belt slipping

Brakes

check brakes

might be a belt like someone suggested and is possibly worth looking into but not likely.sure sounds like a starter issue though. I would start with the belts just to save some cash before a starter.Although, reman staters are pretty cheap as well.Good luck and Good selling