Thanks for the support Northstar,
for some reason I can not find the check box anywhere to initialize it.
Anyway after some testing I managed to manipulate ‘acceleration’ to blend from 300 down to 0 as I release the W key (input forward), but even as acceleration is taken away slowly - once i release W it is regardless of current acceleration value as if no forward thrust is applying to my character and thus just slides along in a straight line until friction stops it.
therefore I have come to the conclusion that for my character to keep some grip and maintain a turn once I release W, I must remove the actual input slowly over time - ie the 1 to -1 axis that the game controller uses.
how this will effect controller input is something ill have to deal with later :).
this whole thing does beg the question how people are doing car wheel physics if the moment they release input the car just slides off the track.
I guess they are not implementing loss of grip via a changing ground friction value.