I've got a retired (but not forever) 1983 R100RS that's been sitting around waiting for some love. I like the older boxers.
I had a 1981 R100RS that I bought new, it was my sport touring bike when that term wasn't even being used. Loved that scooter! In 1985 when the K100/K75 water pumpers came out I foolishly sold it and bought a blue K100RS. Mistake!
Never liked that K bike, the three cylinder 750s were much smoother and just plain better bikes. Always dreaded getting rid of the old boxer RS. Years later (the K bike was long gone!) I got the urge to get another RS and that's where the '83 came in. Found it for sale locally in the newspaper ads. It looks exactly like my silver '81. It had 25,000 miles on it when I bought it and it looked and ran perfect! I put plenty more on it and was happy I had a boxer back in the fold.
That being said I would LOVE to have a R90S!! A friend in college in the mid 70's had a Daytona Orange R90S and I was nuts over that scooter... still am. I'd want a silver if I ever get around to it. Pridmore won the first ever AMA SBK championship on a Butler & Smith R90S in 1976. [moto]
A good friend in Austin, TX still has his 1978 R100RT touring rig (and an '05 GS) and decided to do a complete overhaul on it. It has about 120,000 miles on the clock. He said he had trouble finding any local Bimmer shop that had any interest in the older airheads or working on them. He finally found an independent mechanic (he used to work in a dealership shop) that specialized in the older airhead boxers. My friend says the guy is covered up with work! Lots of old boxers out there still racking up the miles!
Good luck finding your personal money pit! Everybody has one sooner or later. Sometimes they are houses, sometimes, boats... I prefer two wheel pits.
