Ok, i have a question. ML270, been fine all summer, temp gets to just over 80 in about 5 miles. This morning a bit colder, and it took a while, about 8 miles to warm up and reach just over 80 on temp gauge. Normal ? I have been to a Mercedes dealership, was shown a thermostat out of a Mercedes marked box, but it had Behr/Mahle stamped on it, is this OEM ? I can get same on flea bay for half the dealer cost. Just some advice if poss, car runs, starts and stops fine, has heat from heater almost instantly.