I went ahead and scheduled my car to be looked at for a few issues, but you might raise a good point about the highway.
It has been cold here, and I never get on the highway to get to work...only stop and go traffic for about 7 miles. I specifically remember the focus being much warmer when I was on the highway for a trip the other day, so I will intentionally take it on the highway this weekend and see if that makes any difference.
I am not opposed to giving a car time to warm up, but I am not sure what good it does me if it takes it longer to heat up than I will be in the car. Normally 30 minutes is about as long as I am ever in any car I drive (most of the places I go are really close to me). Maybe my old car spoiled me? Normally within 8 minutes of turning her on she was pushing out fire.
In any case, it can't hurt to have it looked at with the other "agenda" items on Tuesday.