Lock your wife and your dog in the trunk of your car for 20 minutes. When you open it whichever one is happy to see you gets the front seat!!! J/K :B
We have a 20# Boston so riding in the back is a non issue with us BUT IMHO she would be safer in a secured kennel in the back of the truck in an accident vs flying around in the cab with 300 mph air bags popping off.
We do have a kennel secured in the back seat where she rides most of the time but we leave the door open so she can sit on DW's lap occasionally.
On a side note, years ago, I read where a little town, Clarkston, WA, passed a city ordinance that dogs could not ride in the back of an open pickup. Kids? No problem, they can ride in the bed but the dog goes in the cab!!!! Don't know if it is still in effect or not.