Is there anything you can do to prevent carsickness?

Yes: Sit in the front seat, there is less "shock" that way. Otherwise, you can try over the counter dramamine, compazine (prochlorperazine)...As always, make sure you are well hydrated.

Yes: Car, or motion, sickness occurs when you inner ear gets out of balance during movement causing nausea. Avoiding reading or playing on your iphone while in car or on boat can help as can sitting in front and watching the horizon out the front window. Medications can help (dramamine, trans derm scope) prevent or treat (nausea rx such as zofran) also.