@alyssa Front seat if possible, either way keep your eyes on the front horizon as possible. If you can't see it, iPhones have some sort of dot-based artificial horizon you can enable. Dimenhydrinate can help but it makes most people drowsy (there are "non-drowsy" versions and alternatives from many vendors). Scopolamine patches are kind of the nuclear option but work well, though they're a prescription in the US, need to be applied in advance, and alcohol is somewhat contraindicated on them.
@alyssa ginger (tea or candy or whatever) seems to help tho perhaps just placebo