I dunno if they did... Should they have, or should I have asked them to? Hmmm the car is going into HP-F this wednesday for an unrelated problem and a service so I'll get them to change the filter... In searching the past threads on pretty much the same problem, I read somewhere that this can be tune related, an idle setting when the car is tuned can be altered.. The person in the particular thread said his idle was set at 450rpm, he had problems and then got it raised to 500 or 550 rpm by his tuner, and the problem was gone... Then I read about TPS, drilling holes in the throttle body, changing whole throttle bodys etc... There is no easy fix, just a few options to look for I guess...