I spot from the truck, try not to slow down much so they don't know I've seen them, park out of sight, come in from the side.
If can I'll put the wind coming from them to me.
They can usually hear you crawling, walking at 175 yds, if the wind is quartering to them but not enough they can smell you, then they can hear you up to 400 yards away.
Expose yourself in white outfit only as little as you can
If the ears or head comes up at all don't move until it goes back down.
I've read their body language if they are awake and can tell if they are soon getting up to walk off.
I have crawled nearly a whole half mile to keep from being spotted, shoot laying down only, unless it's close and there's no choice.
They don't normally fall asleep like a red fox
Sounds like a hoot! My dad used to fox hunt in Iowa before the coyotes showed up, sounds like your methods are similar to his. I've never caught one bedded where I could see him from any distance, but I'm not looking for them either. Most of the old beds I find are in the thick stuff.
I shot 78 fox one winter just before the mange wiped the fox out 33-34 years ago.
Then coyote moved in and exploded in population.
After stalking my first couple coyote I quickly realized I had to change my method with coyote.
Fox will fall asleep after,8am, most coyote don't, or they sleep with one ear, one eye open lol
If you bump or miss a fox most don't leave the section, coyote will easily run four miles before stopping.