Crossdraw works quite well in a vehicle.
There are some dedicated car holsters
Mitch Rosen Counter Carjacking Rig (CCR) https://mitchrosen.com/products/holsters/belt-holsters/
Andrews Leather Carjacker Crossdraw http://www.andrewsleather.com/traditional.htm
Have you looked at https://azulagunholsters.com/product/seated-cross-draw-handgun-holster/ they ship fastI've driving my son from NorCal to Ft. Worth in August and I'm looking for a holster that's easy to wear and access while seated. Likely a G26 or a K6s. Any tips, good or bad?