both thermostats were Starline from EuroCarParts in the UK. Last year the car started occasionally dropping temperature when travelling on motorway. It then eventually stopped getting to operating temperature... I replaced the thermostat... it started behaving same as the old thermostat. ...I replaced it and within a week it failed again. Every day it was taking longer to warm up.
Cons: failed within a week, not holding temperature
Vehicle:
Toyota Celica
