the element ones seem super nice, especially for small sports cars that no one is going to deal finding a full size mount and stuff for them. Just toss one in a glove box but sadly they bearly do anything in the real world. they work mainly by using up the oxygen the fire needs, but if the fire has good air access, like under a car or it's windy. it's not all that useful. there is of all things fire aerosol cans that look to work pretty well for what they are rated for, and easy to store. better than nothing and on a lot of cases the smaller car ABC extinguishers don't actually have enough volume to do much but fart a little at the flame. a good 5 or 10lb is what's needed for a proper fluid fire.
had a buddy with an impala back in the day, he had a shop install a tranny temp gauge, on the way home he's stopped at a light and someone yelled at him his car was on fire. he was like wtf, got out and looked. fire under the car. grabbed his little one, he said it sprayed for like 3 secs, he said it didn't have any effect and he watched it burn to the ground in front of him.
shop installed the wrong hose or something, tranny fluid spray caught fire and it was over. the tests I've seen from these aerosol based fire cans, it's a wet high powered (for a can, like say wasp spray) meant for grease fires in RV stoves. I think he'd have better off with a can or 2 of those. that said, I still haven't bought any haha. keep meaning to order a 4 pack and toss one is the cars cause knowing me I ain't mounting a 5lb bolt in my corvette and that thing is plastic lol. he got secs to get on top of a fire or they are gone.
