(I think its the season for it?? 
)...Basically, the car seems to be engine braking more harshly than it has done in the past, and my aftermarket boost gauge seems to be showing a bit more negative pressure in these cases too.
.... Tonight I returned to the car after some shopping, and left the engine idleing while I demisted the windscreen
(didn`t switch on the rear demister before you ask! 
)- and the revs seemed to drop to around 600-700 rpm, and the lights dimmed. I had to blip the throttle to get it back to normal, although the engine didn't sound like it was struggling or going to stall........ all very odd! I have an n/a with turbo conversion, so still have the battery level indicator. Seems to be charging fine, and the level is nice and high with just the ignition on.Its due for an oil change
(and probably a service), and I think it may have a sticky thermostat or temp sensor somewhere. Any ideas if this would effect things like this?Guess next step is to check if any error codes have been stored by the ECU.
.......? - Ian.