J.B.
Our daughter started getting car sick off and on about six months ago and we solved it easily by switching her from backward facing to forward facing. She was just barely over the 22 pound suggestion for switching, so we tried it to see if it would help. She hasn't been sick since we switched her. If your little one is still facing backward and she's at least 22 pounds, switch her around. Also, avoid giving her any books or toys - and try to get her to look out the windows. Making our bodies aware of the movement will often help ease motion sickness.
As far as sleeping, our daughter did this for a few nights. The first two nights, we thought something was wrong, so we kept going in to check. She would want to talk and play, and then would cry when we left. I finally realized we were "playing into the trap" and I stopped going in. There was one time she cried for a good ten minutes. Then she fell asleep and that was the end of it. My husband hates the "cry it out," so we've agreed that if she cries for more than 2 minutes, I go in and at least make sure she's ok (no poop or puke, not caught in the blanket, etc.). Then I go through the shortened bed time routine again - lie her down, pat her back, turn on her music/light player, and leave. If she cries after that, it's at least five minutes before we go back in. After a good five minute cry, she either falls asleep or is so exhausted that when I do go in a second time, she easily lies back down and is asleep in a minute or two.
Our daughter also loves her music/light player. She'll stare at the lights projected on the ceiling and it distracts her enough to let me leave the room. If she is cutting her molars, then the pain could be waking her up at night. I've used the homeopathic teething drops before and they seem to work fairly well with our daughter. I think we got them at Target and they have a picture of Pooh and Tigger on the front.
Wish you the best!