After I sold my e36 318is I was going mad looking for an e30 318is and after trying everything on donedeal / adverts etc etc I resorted to just walking around the streets of Dublin literally stalking cars and ofcourse when you have something in mind you start seeing it/hearing it everywhere, I recognised the sound of an M42 a MILE away and I would sniff it out!
There were a few really nice ones in various places with no Owners for them to be found anywhere, I left some notes on some (to no avail), there was a particularly clean standard one that I kept hearing while walking around that drove passed me a few times which I eventually tracked to the rathfarnham shopping centre it belonged to an older gentleman who worked there who had for a long time and kept it in great condition, had a chat with him about cars and BMWs and told him my story, but unfortunately it was not for sale for any money. And that's the story of how I gave up on buying an e30
All in all, it's not a success story... But at least I know I tried! and I'd do it again if I was looking for a particular car, bit frustrating at times but kinda fun