Im buying a2001 Audi A4 2.8tiptronic i think this is a great car but it has problems. ...help me know if im pa?

I think im paying too much. The Guy I buying from is a attorney who is my friend. He doesn't have a carfax for me. I not paying for it either. Has body damage. Was t-boned by a van. Damage is fixable. Check engine lght stays on for two days then goes off.coolant sensor is out or something cuz the info system screams at me every time I turn car and headlights on. The undercarriage of car doesn't sound right. Like my axel isn't even attached. ??? Frnt & pass door in info panel says those two doors r open wen they aren't. I was told he thinks its bluebooked at 5 or 6 grand. But not in that condition right! Has 138k .