My border collie used to get car sick all the time. A good seat cover could help manage the mess (though my girl would always push it to the side and puke under it..). As you mentioned in your post, not feeding for a few hours before travel can also help. Like a lot of car sick people, she was at higher risk during longer trips, through curves, or over bumpy roads, so I tried to minimize those as much as possible. If you're giving Benadryl (a very similar acting drug to Dramamine), make sure you're giving it at least 20-30 mins before traveling to allow it to take effect; otherwise you run the risk of her just vomiting it back up.
I'd also suggest taking a look at her behavior in the car to see if she might be experiencing anxiety or stress, which could cause or contribute to her car sickness. If you notice her looking uncomfortable (drooling, shaking, etc) very early in the car ride, or perhaps even before you start to move, that's a good indication that at least some of her sickness is due to anxiety. Maybe she already feared car rides to some extent, which made her feel ill, or she's always been prone to car sickness and has learned to associate being in the car with feeling sick causing her to be even more likely to vomit, but reconditioning her to enjoy being in the car could help a lot. CC/DS work focusing on preparing to leave and getting in the car, working up to actually driving can help her form positive associations with travel.
Train is good option for that and your dog sickness become less then you go in car with her. i also travel by train with my dog and some times i was book ticket at the time of journey. http://loginirctc.net/how-to-book-tatkal-ticket/ (How to Book Tatkal Ticket)
Making the ride cozy will help a lot. Look into this article that I found https://www.pupaholic.com/blogs/posts/traveling-with-your-pet-for-holidays I hope it helps.