Replaced my thermostat and coolant temperature sensor after noticing the engine was taking longer to warm up on cold days and getting a fault for coolant temperature range. After draining the coolant I started to remove the two bolts securing the thermostat housing (plastic) and one sheared clean in half inside the hole!! ..So a 30 minute job turned into a 'mare. I had to drill the old bolt out very slowly which was a b!tch to do. Got a couple of replacement bolts cut them to size and fitted all the new parts. Car is heating up much faster now and holds a more constant temp which is nice.