I had the larger Coleman roadtrip fridge
for my pop ups. They work reasonably well. They DO draw a ton, so I wouldn't recomend using them solo without a hefty charging source. Most have AC adaptors and I used mine when in RV parks and they seemed to work great.
Yes, leaving in sunlight hurts quite a bit, and when the ambient temp outside is over 90, they keep things drinkable, but I would not store perishables in it.
I have a small console one in the car and it works wonderful. Holds a six pack and a couple sammiches for the road. It pretty much always has soda (POP!) in it for my commutes, so it is always running when the car is running. Has held up well.
I forgot the brand tho.. wal mart special.