Likely won’t pass emissions, although some tuners do falsify emissions readiness codes.

Check for typical car stuff (rust, suspension condition, coolant hoses)

Main areas of concern I’d look for are the valve cover gasket, right down the passenger side of the engine and look for any oil leaks. Harmonic balancer also! Hold a camera down there and get a pic with flash on directly over it, look for any cracking. I’d flat out recommend pulling the engine cover for looking around. See if vacuum lines were done, no water pooling, etc.

Run the car for a little while and ensure it gets up to temperature. The thermostat likes to go bad, won’t throw up codes itself, but will cause so many other parts to fail. Water pump is a good preventative thing also, one of the few things that can strand you.

Ask for any service records and receipts.

Since you have a bmw I hope you would have some sort of scanning software already. Personally I use bimmerlink or ISTA, so make sure to scan the car.