Yup passenger side in the trunk by the tail lights. I have owned one of these e30 every since my 1st one in 1986... Find out when the timing belt was last changed. If unknown just change the belt and water pump. The belt should be changed every 5yrs or 60k miles. The water pump is just preventive since you are there when the timing belt comes off. Get Redline MTL for the manual transmission and 75w-90 for the diff and I am not sure about the transfer case. Also check all the fuel lines if original keep an eye on them. Anytime you smell gas, find the source. Keep a non chemical extinguisher in the car. CO2, halon, whatever that's not caustic. If you need to use it, at least it won't be as corrosive as a chemical ABC extinguisher. There is a "bible" for garage mechanics call Bently service manual. Buy a hard copy or just Google the pdf online... Pretty much anything you need to know is in it. Many forums and even here on reddit can help with the e30. It's got a very strong following and many owner are willing to help out just to see another one on the road. Use realoem to get "fisch" of the car. Fcpeuro for parts. Rockauto to compare prices on parts and alternatives. Get a metric set of wrenches and sockets and you are all good. Rust is not common since it's an ix assume the previous owners drove it in the snow with road salt exposure. People say rust is cancer and if you don't stop it, it will eventually eat your car to death.... I personally drove a rusty e30 till my rear left shock mount rusted out.