I don't get motion sickness from using the SRV at any of the sites, I have never had sea sickness either which is what most of this is about and why people in VR get sick. There are tricks one can use to offset the motion sickness as VR motion sickness is a mild form of sea sickness.
First make sure you're not dropping frames when using the SRV, if you are lower the video settings bit by bit till they stop dropping.
Don't look at the horizon as you move it is always in motion, your inner ear and brain can't handle it moving when you are on solid ground. Instead look at a middle spot and unfocus your eyes. I tend to look at the top edge on my scanner and not focus on it or anything else till I have to. I can still see things clearly and know where they are when in motion, so you are not going to crash.
Motion sickness comes from your inner ear and brain not being able to register what your eyes are seeing when the horizon rocks around, which is the main cause for sea sickness or any other motion sickness.
For me though most of my problems went when I stopped the frame rate drops in the VR headset. Also the more time I spent in VR in a SRV the less nausea I felt, because you can train your brain and inner ear to ignore what the eyes see.