I was wondering if anyone here has personal experience with any of these, for use in cars (Subarus

I'm thinking I'd prefer an icebox, maybe a 25L one
as they seem a good compromise between chill-performance and volume-vs.-price.
I thought about a styrofoam one, but I think I'd probably abuse it too much with all the stuff I pack into my wagon.
I'd like to leave food and drinks in my car for days at a time, grab something when the mood suits.
I don't want to have to load up a cooler every day that I might want a picnic lunch at the beach.
Pretty soon I'll need something in my car to keep cold groceries from spoiling quickly.

Are any brands of iceboxes better than others for ice-retention?
I had a Coleman X-Treme cooler back in Canada that worked very well.
But they don't make the X-Treme in the size that I want.
I'd like to leave something behind the front seats on the floor.