on really cold mornings when i start the coupe the revs like to dance about between 700 and 1k rpm for the first 10 seconds, it doesnt happen on every cold start just on the days that are around 0. car has just been serviced but still has the problem, and the guy also cleaned out the idle control valve + throtle body. im thinking it may be thermostat related? any help appreciated!

When you say dance about do you mean its constantly going up and down for them 10 seconds? If so i think it could be your TPS sensor, there is a thread somewhere about this, its quite common. Mine usually goes to about 1100 - 1200rpm when first started until about 5-10 seconds and then idles perfect at 700rpm. I was told by hundai that this was normal and is like the "choke" equivalent of older cars.

like you say it only does it on cold mornings......its the choke dont worry bout it