Not currently, no (I believe you have to re start it after you put the car in drive, as you state). I dont have first hand knowledge though, as I dont mind paying the $9.99 for premium connectivity.
Since I dont use my phone as a hotspot, I use minimal cellular data, and my cellular carrier reduces my bill $10 a month for that, which pays for my car data for me.
I also dont consider the cost of a fast food meal to be too expensive for mobile data, but understand those who do.