speed sensor wire help

hi all, i'm really stuck on this one. I've just bought a pioneer sat-nav unit and i'm going to install it myself, problem is i need to find the speed sensor wire that comes from the ecu. can anyone help?

Is this for a P38A or a Classic? Your profile only shows your car as a 1995 model?

Ron

its a p38 m8

ok an update, i've fitted the sat-nav and can confirm the speed sensor wire is the yellow wire going in to the dash, phew it was a lot of work but looking sweet.http://memimage.cardomain.net/member_images/8/web/608000-608999/608684_9_full.jpg