Don't get me started on lumpy idle.......I am having issues with that, but got an idea how to sort it. Some pointers in this thread if you need
http://www.cliosport.net/threads/injector-issues.792412/
My thermostat has been like this for over a year now. Yes I know I am lazy seeing as I have the thermostat ready to change!! My temp sensor was initially broken as as soon as the gauge got above half the needle would drop to stone cold until the car cooled and then it would pick back up to where it should be, sometimes the needle didn't drop to zero when the key was removed, just sat above zero. Got sensor and thermostat to change, changed the sensor and that worked but I didn't get around to the thermostat as it seemed to have fixed it, but I didn't get the car proper warm to test it.