One's climate, local public safety, and time exposure of the vehicle to the elements has everything to do with what you might or might not do with truck-and-car binoculars. Here's what works for my situation:
In my central Arizona environment, the concern is with heat. As I am retired, my vehicles are only out in the elements when I am out shopping or dining. They don't sit outside in the sun all day long. And the crime risk, where I frequent, is very low. Otherwise, the vehicles are at home in my garage (which is also hot for half of the year). I don't feel the need to use low-cost binoculars, because I don't subject them to much risk at all.
What I do is, I have a padded, slim and very compact camera shoulder bag. It's about the size and shape of a pair of 7x42 bins. The bag is just large enough to hold a pair of compact Leica UVHD+ 10x32 bins and a very compact m4/3 camera.
It's got outside pockets, front and back, as well.
When I am about to leave the house, I put the 10x32s in the bag, where the little camera already resides.
And, I slip one of those small (frozen) freezer bags (typically used for keeping perishables cool while being shipped) into the outside pocket.
When getting in the vehicle, I place the camera bag under the driver seat. Between the blacked-out window tinting and these sitting under the seat - there is nothing to lure a break-in. And crime is very low in our area.
The freezer pack, in the outside pocket, keeps the Leicas and the camera nice and cool, even when the truck or SUV gets hot inside during a lunch, or while shopping.
When I get back home, the small camera bag comes back in the house, and freezer pack goes back in the freezer - the Leicas and camera are not left in a vehicle at all times; they are only in the vehicle while I'm out and about.
This approach takes a little more effort than just leaving a pair of bins in the vehicles all the time, but at least I'm always using top-deck binoculars, home and away. And always have a competent camera at hand, as well. Works for me.