I've got a few nice pistols, but I bought a Hi-point to keep in my truck. It was $175 new & a lifetime warranty. I had a Glock stolen from my truck & will never keep anything but a less expensive gun in it. There are some good suggestions here, but I'm a Glock man.
Was going to recommend something similar. If you ever have to use it, it'll probably be at a distance of 6' or less. So any make will work good as another. I keep a used beat up $150 9mm in my vehicle. I actually have a blade type conceal holster clipped under my steering console. My other pistols are Kimber, Colt & Glocks. I'd rather take a chance of a $150 gun getting stolen vs a $600 $1,200 gun.