There is no oil or water temp gauge on my e90 323i. Initially I was bothered by that.... but after two uneventful years... I'm used to it.
I presume the car will warn you or put the car into limp mode should the oil or water temperature get too high and throw up a warning light. The fear is always whether the car can catch the situation in time before something catastropic happens !!! ha ha.... The fuel economy gauge is useless, I would trade that for a water or oil temp gauge anytime.
There is no oil dipstick as well.... just have to rely on an electronic gauge... all in the name of technological progress ?