1-the spinning ignition key is fairly common problem in E36 (body code for 3-series cars of certain model years) BMWs. the lock cylinder must be replaced-- make sure it's keyed to your existing key. probably a dealer has to do it. 2-'check engine' light comes on at the slightest hint of an emission control problem. make sure the gas filler cap is properly closed. don't put in more gas after the nozzle shuts off automatically. drive the car about a week. if the light stays on, a technician will have to check the computer fault codes and figure out what the problem is. could be just a minor thing... no problem driving with that light on for a while... if the engine's running ok.