Misting up - bsw
During this wet weather my car, a SWB Colorado, always mists up when it's left parked whilst I shop or walk the dog. It takes me longer to clear the windows before I can drive off than it does to drive home. Can anyone recommend a product that I can apply to the windows when they are dry which will prevent this.
Misting up - No Do$h
Can't think of a product but are you using you aircon to demist it in the first place? Sometimes the aircon will retain some of the moisture, leaving the car more humid on subsequent start-ups.

IIRC, the Telegraph were doing an offer about 3 weeks back on some kind of treatment to stop misting. May be worth checking the main Torygraph website.

No Dosh
Misting up - Dynamic Dave
Can't think of it's proper name off hand, but the stuff bikers use for their visors. Fog Guard maybe??
Misting up - frostbite
A few drops of low-foaming detergent on a cloth is a handy way to reduce misting tendencies.
Misting up - JamesH
Air Con does a good job of shifting the mist but leaves it in a worse state the next morning.

To get out of the vicious circle, I have used CarPlan Crystal Clear for a few years now. It's a glass cleaner but has an anti-mist agent in it. I can only find it sold in Homebase now (after a long hunt). It does a good job on my screen.

Misting up - J Bonington Jagworth
Turn the air-con to cold (or turn off the heater and open a window) shortly before you get to your destination. Warm air holds more moisture than cold.
Misting up - volvoman
I've tried two products Rain X Anti-Fog (from Costco) and DuraShine Fog Shield (QVC). Both work well !
Misting up - Dave_TD
Can't you just turn the aircon off, so it doesn't filter or dehumidify the air at all, once the windows are demisted?
I don't have aircon, and when it's raining and lots of wet people are getting in and out of my car, the windscreen and front side windows stay demisted by the power of the fan alone.

Failing that, as HJ says, you must have a leak. When you get in and it's all misted up, feel all the carpets for wet patches. Most common places are under the dash or in the boot.
Misting up - bsw
Thanks everyone for the suggestions. I'm going to try to track down some of the products mentioned.

I don't think that the problem is that the car has a leak. The water is introduced when I get back in with wet outer clothes and a big wet dog. The demisters and heated rear screen do a good job on clearing the back and front screens, with or without the aircon, but the rear side windows take a while to clear and are difficult to reach to clear manually. I don't like driving "in a tunnel" hence the desire to find something to stop the mist forming in the first place.

Again thanks for the input,

Misting up - Dave_TD
Again I don't know about your car, but in all the cars I've had the airflow from the heater is only designed to demist the windscreen and front door windows, I've never had a car that demists the rear side windows effectively. Hence the heated element to demist the back window! You could try opening the front windows a fraction whilst driving along, this seems to help.
Misting up - Peter D
Check all the carpet for dampness or the back of the car where the dog lies. You may have a leak somewhere which is increasing the humidity in the car in the first place. But a heater in the car for several housr and in different positions to dry it all out. Be carefull and leave the windows open by a couple of inches. Peter
Misting up - Shigg

Did you try the Durashine polish as well?

Misting up - volvoman
Yep - and the Durawash. Not impressed by either I'm afraid. Seemed to leave a permanent 'haze' on the paintwork which is still visible many months later.
Misting up - Shigg
Thanks for the info! Well sort of long lasting I guess.

Misting up - J Bonington Jagworth
"The water is introduced when I get back in with wet outer clothes.."

A common problem in recent months. I had a car that had belonged to a lifeboatman, and I'm not sure the driver's seat ever dried out completely! It might be worth buying a seat cover and putting an impervious layer (e.g. polythene or proofed nylon) underneath it, which would limit the amount of moisture transferring from your clothes. Still need to dry the upholstery out, though - a small dehumidifier would do it.
Misting up - delboy100
A faulty heater matrix can do this as well I believe.
Misting up - kithmo
I find that if I close the heater vents completely ("0" or dot position on the airflow direction knob), just before the journey's end, then the windscreen does not mist up as much as if I leave the vents open. Also, if doing a lot of short journeys, keep the heater on full heat and open windows to regulate the temperature this promotes good air flow and a regular change of air in the vehicle and gets everything dried out (including the vents).
Misting up - L'escargot
In my experience, with a car that has a tendency to mist up when parked (especially if it mists up more when it has, or has had, the sun shining on it) it helps if you park with the windscreen facing the sun. Misting-up mostly occurs on the window that faces away from the sun. Whereas few cars have a heated front screen, most (if not all) cars have a heated rear screen.

Value my car