I've bought a secondhand Zafira 10 weeks ago, which was serviced a few days before I took ownership. The front brakes are now screeching like a banshee and before xmas, we had to put loads of oil in it as the engine started rattling. There appeared to be no oil in the engine. There is no sign of burning oil from the exhaust or dripping oil on the drive! What is involved in a service and how can I find out if it really was serviced? Many thanks in advance.