The regular antenna is in the back window, so this is true. As far as wanting to use Mobile One... you can get a Quick Lube type place to change it without it voiding the warranty. Just keep the reciept as a proof of the routine maintenance. Also do not allow then to check the rear end ect. for levels. There is a seal and if it is broken then it voids the warranty. So just tell them the oil and nothing more. That is what I do when I'm outy of town and have to have the oil changed. Tire... I can't help you there. I live in NC and SC and we don't deal with much winter weather. I would wait a while on the synthetic oil. About 6000 miles to let everything settle. Then add the synthetic for the rest of your cars life. Some might disagree but thats my take on it. Good luck and enjoy the ride (even if its slippery) LOL