Schedule Disruptions How to Manage

Hello! I have a 12mo who has recently moved to 1 nap (5/6).

Usually wake 7.30, Nap 12.30-2, Bed by 8.

This schedule works amazingly for us when we're at home all day but my trouble is she will fall asleep every single car ride without fail. And we live about 20 mins away from town which I feel like is long enough to reset her readiness for a new wake window, so I can't really even align it and transfer her at home.

Does anybody else have a similar issue or any tips to keep her awake in the car? Or any tips on how to not let it derail our whole day/night?

It really disrupts our day and she ends up having awful split nights because she's not tired enough I think due to 40 mins+ extra napping a day.

For example, tonight she napped on the drive home from the park (woke at 4.30pm) so went to sleep around 9.45pm and was awake again around 1. I know this is so bad and hard for her but not sure how to help.