quick question

IT may be really cold where you are but you only need to let your car warm up for about a min. until the RPM drops, check your owners manual
Road salt itnt too good for your car either you might want to take it to a car wash to wash it (itll only take 5 min and you just get to sit back and relax while others freeze their nutz off)
i also have a 2002 sonic blue 3.8l Less than 2,900 mustangs were painted sonic blue for 02 outta 130,000

SonicBlue02-3.8:

I will second what Double T says. Do not let that road salt eat up the bottom of your car! Unfortunately our cars are really prone to rust when exposed. This salt is just the thing that will cause that exposure and compromise your chasis.

Doc

I have been driving my 2002 V6 Mustang now for over 2 years here in the New England snow and salt. I have put over 18,8xx miles on it since I bought it brand new. What I do is I go to the car wash and spray my car thoroughly underneath the undercarraige areas and also all around the exterior. I have driven in many snowstorms and in the salty roads up here and the salt makes the car look all white. I just spray my Mustang with a high pressure gun at the car wash to get all the salt off. I never take it thru the cloth or brush car wash. When the weather gets warmer out, I pay a detailer to detail my Mustang. I usually detail my car 2 to 3 times per year depending on how bad it looks. You have to understand that no matter what, as long as you drive your car in the salt during the wintertime, there will come a time when your vehicle will start to form rust on it. This is unavoidable. Some cars show rust earlier than others. The only thing that you can do is what I do to try to prolong the life of the paint and sheetmetal on the vehicle so it will not rust too soon. With age though, rust will definitely start to show up on the sheetmetal. I am not really sure WHERE the first signs of rust will start showing on the 99-04 body styles. I have yet to see any 99-04 Mustangs with rust on the exterior of their body or anywhere on their undercarraige. Does anybody in here know where the 99-04 Mustangs are prone to showing the first signs of rust on their body and/or undercarraige/frame? I would like to know more about this. Nobody has ever raised this question in here before. Thanks.

Some car washes offer an under carriage wash for an extra buck. Unfortunately, after I lowered mine, I can't take it through my favorite car wash with the freezing nut kids on the other side to dry it off, as my lower control arms hit the guide rails. I now take it to the lazer type car washes once a week instead.

Some garages offer an under coating that consists of oil and kerosene, I think that's what the main ingredients are? I know a place around here that does it and a few people I've spoken with swear by it.

I recommend washing the car once a week during the winter.

As far as idling goes, I wouldn't think that much gas would be burned up. As mentioned above, you only need to wait for the idle to drop before you go tearing off, but if you're waiting for the car to warm up, that's the trade off between comfort and cost. Your decision.