These days, that particular story is changing; a good 309 GTI is respected by enthusiasts and looked upon with fondness and reverence. As it should be. But there are still plenty of other cars that live in the shadow of a more favoured sibling - and while that might be unfair, their relatively unloved status means, you've guessed it, some used car bargains afoot.
I give you, for example, the Mk2 Ford Focus ST. In its 'ASBO' Orange glory, it was once famed in McDonalds car parks across the land, but the advent of the more powerful Focus RS and gleeful Fiesta ST have both left the Focus sitting at the back of the classroom. Don't forget why we loved it in the first place, though; quick, sure-footed handling backed up by a storming engine that managed hairy-chested torque while also goading you on to ever-higher revs. And threw a terrific five-pot warble into the bargain. Yet the ST is also a terrific all-rounder, capable of cosseting in the cruise and about as practical as they come. All this for considerably less than £5,000 - indeed, this one, in a very tasteful black-over-grey colour combo, has done below average miles, has an exemplary history and is yours for no more than £4,199 - which has to be a £4,000 haggle all day long.
Staying with Japanese performance cars for a sec, the chances are you probably can't - or won't - afford a two-year-old Nissan GT-R NISMO, especially at around £110,000. Next to that, £28,950 for this 370Z Nismo feels like a snip. OK, the 370Z can't deliver the brain-twisting performance of the GT-R, but 0-62mph in 4.8 seconds isn't exactly to be sniffed at, and it'd be more than enough for me. Throw in meaty handling which rewards the driver who shows it who's boss, and it becomes quite a tempting thing.
Mind you, a car doesn't have to live in the shadow of a sibling to suffer from the 309 Effect - it can live in the shadow of a rival, too. A case in point is the Jaguar S-Type R. You may scoff, but the R was in fact a stonking performance saloon, with terrific chassis balance and a delightful propensity for lurid tail-happiness. That V8 sounds exceptional, too, particularly if opened up with an aftermarket exhaust system. Yet of course, the main reason you'd have to think twice about buying one has always been the E39 BMW M5 - a car which always had the legs on the S-Type, just, and furthermore which came with a manual 'box.