If you have a truck put it in between your seats it'll sit pretty secure there. And for a little added security you could put it in an IWB holster and then put it in between seats.
i use a Gum Creek vehicle handgun mount and picked up a blackhawk nylon holster to use with it. it mounts under the steering column, really easy to access, and the holster holds an extra mag too. I dont believe its considered concealed but as long as you have an indiana license to carry your good to go.
On really long drives, I do the De Santis Apache left ankle Glock-27. Only fast food and pee-pee/potty breaks in between, works for me, I carry the clamshell from Center of Mass for hotel room stops.
Mine is always in a holster. My every day carry holster is a Crossbreed super tuck. On a long trip I will sometimes use an appendix holster. But I keep my weapon on me at all times.