[denisond3]

Was the car using oil a lot prior to having that shop do the oil change? And how many miles are on the engine? Rear main seals arent particularly close to the exhaust manifold, and are well protected by the bell housing of the transmission - so a 'problem' with the exhaust manifold does not seem at all likely to me. It is quite possible the shop didnt put a new plastic washer when they put the oil plug back in, and the oil dribbled out around an old squashed/defective washer. In this case a new oil plug and new washer would take car of it. Its also possible they didnt get the oil filter re-installed properly, and that let oil leak out. This type of leak would only be while the motor was running. Its also possible they only put in 3 quarts instead of 4, or even 2 quarts instead of 4. That would make it seem as if the car were using oil quickly. Im not saying the shop is being dishonest or has a hidden agenda; it can be human error and being in a hurry.
Most of the time a rear main seal will begin to leak slowly, getting worse month by month or year by year. For it to start leaking badly in a sudden way - that would be fairly unusual; though not impossible. If someone put Automatic Transmission Fluid into the engine, it could sofen up the main seals drastically, and they would start to leak fairly badly.
Im going by what my 90 Jetta looks like under the hood, as I think the driveline in Jettas and Golfs are very similar. Jettas just have a bigger trunk than a Golf.