When, as a 23yo fresh-out-of-college car guy, working for a VW Mail order place in Colorado, I got to help the BMW department head on the weekends maintain his BMW vintage race car fleet, I was floored. He got free labor (kept me fed and watered) and I got to work on old cars.
One day, while working on the phones, he came and said, "Punch out, we need to go test the cars and you can help." The owner of the company, myself and the BMW guy all went down to his house, loaded up a couple cars and went to a local track (on a weekday, so had it all to ourselves!).
The cars? There was a 1975 E21 BMW 320I that was in an SCCA GT3 (I think) configuration that had box flares, super peaky engine, and everything else you would expect. The other car was a Group 2 CSL that made all those lovely 6cyl noises, had the alternator driven off the diff, etc.
I assumed I would be there only to wrench and help load and unload, but after getting the 320i started and idling, he threw me a driving suit and said to take it out! Was awesome. After many laps, I came in, made some notes on things I thought needing adjusting, and then he pulled in in the CSL and told me to take it out. I said no, I can't afford to buy that, let alone repair it, and he flipped me the bird and told me to drive it or walk home.
So I did. It was awesome. HUGE slicks and awesome power, very balanced, etc. I was doing 7 tenths until he came ROARING by, tires howling, in the 320i, again, flipping me the bird and waving me to come on. So I wicked it up. I don't think I ever pushed 10/tenths, but at 8 or 9 she was awesome. I remember coming in and talking about the alignment, front toe-out specifically, because it was darty under heavy breaking, and they found it had almost an inch toe out! Good memories.
Here's the CSL - the E21 I have photographs of in a box somewhere...
[URL=http://s61.photobucket.com/user/greggearhead/media/BMW/3af6fb74d37f0edc9b8e5e996f1eb1e5_zpssxkulzgh.jpg.html][/URL]