I thought it would be good to create this Wiki listing out and possibly linking to all the different car genres and modifications and groups.

Starting out:

Classics (era?)	Link
Drifting	www.driftworks.co.uk
Kit Cars	Link
Military Vehicles	Link
Luxury Barges	Link
Rat Look	Link
DTM	Link
Japanese Imports	Link
'Flushed'	Link
4x4	http://www.alrc.co.uk/
Off Roaders	Link

Please add to this list... and possible add any interesting links.

Question: What's the difference between 4x4 and off roaders?