Re: 6 miles spin
There's something wrong with it unless you're giving it huge bootfuls in the wet.
Twinsparks do eventually break away at the rear but it all happens in a very predictable and controllable fashion.
Have a look at-
1. The rear tyres, are they bald/crappy no-name Chinese.
2. Rear wheel bearings, these can wobble around quite alarmingly without making any nasty noises.
3. Rear suspension bushes. Lever around with a big bar to check for play.
4. Dodgy aftermarket springs or antiroll bars. Fitting hard springs to the rear without correcting the front to match will make the car very tail happy.
5. At the front, check the tracking, excessive toe-in can make the car a bit "pointy" (personally I like this...), excessive toe out will make it understeer.
On the subject of... The manual says the 75 should have 1 degree of toe out but I've found that this makes the car feel stodgy as well as wearing out the inner edges of tyres. I set my front wheels parallel or slightly toeing inwards for sharper turn in.
Alfa 75 TS LE Veloce
Fiat 125 Abnormale