I have just had my a6 2.8 se 1999 in the bodyshop for a new front bumper. On going to pick the car up I find that it will not start!

Had a diagnostic check run over it and no visible faults. The car will turn over but won't fire up.

Before I took the car in the hazards did not flash when the doors were locked or when the hazard swith was pressed........since having the new bumper they work! Weird. This could just be coincidence?

Could this be alarm/imob problem?

The injectors are working fine and the computer says that the fuel pump is working.

Any ideas? anyones help and advice would be much appreciated!