Chiswick
Lovers Lane - lots of action alone there, go over Hammersmith fly over towards Richmond when you get to the first round about there a petrol station on your left hand side, take the 2nd exit from the petrol station where the one way fly over starts, then keep driving till you get to a bridge with a set of traffic lights, turn left, this takes you along the river and all the way round lovers lane. plenty of action at night and lots of places to park and have fun.
Clapham Common
Mainly Gays although you do get the occasional couples putting on a show.
Dulwich
The lane that leads up to Dulwich golf course just by the tollgate - Very busy at weekends there's normally one or two couples in cars so lots to see!
Kenton, north of Wembley NW9
Open space / Barn Hill recreation area on the Fryent Way A4140. - Many couples in cars afternoon/evening. Many young Asians. Some participation. Generally a relaxed attitude about watchers.
Hammersmith
Tesco car park on King Street - Known to the locals as 'wife swap city'