Hi, is there a trick for stopping the windows from constantly fogging up? I have to repeatedly open and close both front windows to clear them, and was hoping that there was a way to stop them from fogging up in the first place? Thanks in advance.

Use your aircon / climate control on a day to day basis and get yourself a dehumidifier type bag for the dash to leave in the car to absorb the moisture.

Some rainx anti fog has been effective for me before. Make sure there is nothing damp in the car and some cat litter in a pair of tights will absorb moisture.

It might sound like a daft question but do you have the fan on and the vents open ??

A couple of years back a family friend was bringing her Renault Scenic to mine for a service from her home about 10 miles away on a cold wet winter's day but when she got here the car was completely steamed up inside. She stated that she had had to stop twice on the journey to clear the windows as she couldn't see where she was going. A quick check of the heater controls revealed that she had the "re-circulate" button on so no fresh air was getting into the car whatsoever. I had to explain to her what the re-circulate button was for 🙄🙄

4 hours ago, Phil3747 said:

... I had to explain to her what the re-circulate button was for 🙄🙄

Did you also explain that the indicator stalk was not an optional handbag holder? LOL 🤣

Repeatedly as in more than once per journey?  If so, there's probably something damp in the car...if it's not a soggy coat or a wet dog, check all the carpets for any dampness.  

Alternatively try not to breathe while driving.

19 hours ago, Phil3747 said:

A quick check of the heater controls revealed that she had the "re-circulate" button on so no fresh air was getting into the car whatsoever.

Reminds me of my first Mini. Those only had a recirculating heater. They used to be called "fug stirrers" On a really cold day with the heater on max it could just about clear a hand-sized patch above each vent.

25 minutes ago, mjt said:

Reminds me of my first Mini. Those only had a recirculating heater. They used to be called "fug stirrers" On a really cold day with the heater on max it could just about clear a hand-sized patch above each vent.

Lol, I had one of those. It gave good heat output though.

Apparently we were lucky to have It - it was an optional extra on the early cars. 

True, you could build up a really high temperature in the cabin but the hot air held so much moisture that the condensation would literally run down all the windows. At the time there was a kind of double-glazing plastic panel on the market that could be stuck inside the rear window to keep it clear. From what I remember it was surprisingly effective.

Temperature control was by a valve that controlled the flow of water through the heater.

If the windows are constantly fogging up when the car is parked etc could be worth checking the boot etc for any water leaks. 
 

Seen this on a Fiesta my mother owned, always used to mist up or get condensation inside then found a small pond forming in the spare wheel well 🙄