Though it is winter and I have trac control on, come spring and summer should I switch it off? It goes off at street speeds according to the book, but that little glaring orange light subconsciously gets to me, like a warning. Ditto the same for the A/C. Given state of the art today, am I prematurely wearing out tracs by not turning them off under normal driving conditions? Same with the A/C, which Volvo suggests, between the lines, should be left on. Any thoughts? Dick