This month's irresistible twitching of the thumbs occurred while browsing Silverstone Auctions' September 20 sale catalogue. So what's doing it for me this time? A smattering of rare and undeniably tasty German metallwerk.

Can't help feeling I've missed the boat for that BMW E30 M3 I always wanted. They continue their ever-upward spiral in value, special editions doing best of all. I once wrote a book on BMW M cars and I can now confess that, at the time, I'd never heard of Johnny Cecotto, which is probably why the 1989 special edition named after him was rebranded in the UK as the Roberto Ravaglia. No, the spec isn't as focused as an M3 Evo, but it's rare: just 505 Cecottos/Ravaglias were made. Up for auction is number 230, looking truly gorgeous - as reflected in a stiff estimate of £35,000 - £40,000.

M3 or '02 Turbo? Hmmm...
Amazingly, that's more than the uber-desirable and rare (1,672 built) BMW 2002 Turbo, under the hammer at an estimated £32,000 - £38,000. As we all know, this was Europe's first turbocharged production car, although that's no great advert: the '02 delivered its KKK-boosted 170hp with such chasmic lag that you could finish a full English before it kicked in. Once spooled up, though, it's mighty - I well remember an eyebrow-raising motorway dice with a 3 Series sales rep on the way to a photo shoot in one. This one's all-white with no Motorsport stripes or reverse 'Turbo' logo - very much as it should be.

I'm also rather taken with this Porsche 911 ST. Ah, except it's not a genuine ST - the package of tuning mods that Porsche developed for the 911 (there were just 49 factory genuine STs) - it's an 'evocation' based on a 1972 911T. But what a lovely thing it is: Bilsteins, anti-roll bars, fab 8/9x15 wheels, 2,381cc engine with 240hp, magnesium throttle bodies, close-ratio gearbox and LSD. Once driven by WRC helmsman Bjorn Waldegard it has FIA historic papers and comes liveried in the fabulously-named Hellelfenbein (light ivory). It's not cheap at £75,000 - £85,000, but have you seen the prices of standard early '70s 911s recently?

Rallye good show
Continuing the rare German theme, at Brightwells on September 24 in Leominster, there's a VW GolfRallye. This 1989 homologation special is certainly distinctive, even though I've never been sure about the boxed-arch look, nor the linered-down 1,763cc 'G-Lader' supercharged lump with a limp 161hp. With the heavy Synchro 4x4 gear in situ, the 0-60mph time of 8.6 seconds ain't gonna trouble a standard GTI MkII. But with only 5,000 Rallyes made and lots spent on this example, on the face of it, it looks mighty attractive at £7,000 - £9,000. Ah, but there's a catch: worryingly, this 117,000-mile example is a non-runner with a 'misfire'. Hmmm...

I'm a bit surprised Audi Quattros aren't yet at the same values as the Lancia Integrale. This 1986 'MB' is a case in point: good value at an estimated £11,000 - £12,000, but then it is still Irish-registered, recently out of a six-year storage and has clocked a not inconsiderable 160,000 miles, but at least it has a fully-stamped service book.

Mmmm635CSi
A BMW 'M' car in all but name is the 635CSi. This 1986 black example seems like another bargain at £3,000 - £4,000. Yes, it's done 224,800 miles in its time, but it has a huge history and has been restored. If you prefer your 6 Series to be in pristine nick, this 1979 633CSi may not have quite the kudos of the 635, but looks rather fab: it's done only 34,000 miles. Will it reach the estimated £8,000 - £10,000? We'll find out soon.

I can't resist one final not-very-German German-badged oddity: a Fiat 500 with a three-pointed star grille. Dolled up as a tribute to Stirling Moss's 722-numbered Merc 300 SLR, it's even been signed by Sir Stirling on the dash. Yours for £9Kish.