just use sox
I agree. Use socks.
Fill a sock with kitty litter. If you wanted to do it the easy way you could just tie a knot at the end but if you wanted it to look pretty you could cut off the toe and top & sew both ends. If you had an old flannel shirt, cut out 2 squares and sew all sides. That might look even better.
Cat litter https://www.youtube.com/watch?v=4t4mzMS-ZZ8 other ways?? https://www.youtube.com/watch?v=8-IwmwzaHD0
Keep the vehicle vent setting to allow fresh air flowing in—NOT on the recirculating setting!! Use a/c setting or defrost setting to remove moisture from air inside!!