I had a tricky kiddo like this too - ended up having to do a 20min CN in the AM, really short, like 2hr A time in the middle then long PM nap. The middle A time was miserable so that was filled with eating and lots of keeping him occupied, plan nothing for that time if you can :-/ If you can use the car trip to pick up his sibling for getting to sleep, you could do something like this:
6 - WU (ideally later, I know, just going on what's happening atm)
10:30 - CN (20-30min tops)
12:45 (or close enough - fall asleep in car - transfer to bed when you get home)
Let him sleep max. 2.5hr
BT more like 7/7:30 which will then help with the EW too.
WRT transferring from car to bed, that is trainable, I did it with a standing/walking shush/pat variant and it still works wonderfully for us to this day and DS is now 6yo.