I have a 20v Coupe with speedo problems. When I got car speedo would not work straight off but would come on when warm.

No it hardly ever comes on.

Yesterday i went over a bump and it came on but went off again - co oncidence ?

Garage is quoting £150 to replace speed sensor which seems a lot anyone had any experience of this ?

i'd probably agree that its the speed sensor, no idea of price myself but does seem a bit much, shouldnt be a difficult job.

that or could be loose cables on the back of the dash?