Sorry I should have said, we have wristbands, blacked out windows with sunshades on and if I know we're going further than normal we use the travel sickness medication from boots. I've chosen to keep her rear facing for as long as possible, so that may be an issue, but don't want to face her forward especially if we're going on a long drive across the country.
Same re the rear facing. Tbh, I just keep a stash of sick bags in the car - the ones with the hard plastic ring at the top and my daughter is quite capable of using one if she needs it now and usually tells me when she feels sick. Sounds like you are doing everything you can
No close to face activity's we remove the black out window so could see, lots of distraction and to be fair I turn him forward facing he now 4 nearly and we don't have any issues unless he eats b4 and gets to warm. We keep a window cracked open so it's cooler for hom too and we also put him in the middle seat at the bk which is safer and less rocky for him so yeah we had deffo fewer sickness spells since doing this 😉
Have you tried the anti-sickness travel wrist bands? My daughter gets car sick and she's been ok since tryjng those out. Might be a coincidence because she's very random with when she gets sick