Well here it goes, I've had better results here than with the so called Ford mechanics at the local dealership. When I start the car when it's cold the idle seems a little rough. When I put it into either R or D the idling becomes quite rough and the revs build up by about 2-3 hundred RPM,s. If I put it back to N or P the idle goes back down and I put it straight back into gear the problem has gone. ????

How old are the plugs, leads and cap ???
Check and clean Idle solenoid, it maybe sticking..

Plugs are old and I've got some to change them with I'm just lazy. I've had the car a bit over 4 years and the leads and cap have never been changed. As for the idle solenoid, is that in the throttle body? Anything tricky I need to know about putting it back in?