Cost is something I consider when buying a light for my car. Lots of cars get broken into around some of the places I travel, so I go cheaper with car lights than I do with lights I buy for other purposes.
Since Lowes only carries the 6PL and G2L ( I thought they also carried the 9P? ) , I would go with the latter.
One of the lights I keep in the door of my truck is a Lowes Kobalt 3-Watt. I got it on sale for ~$30. Cheap and it has its flaws, but it is bright and won't cost too much to replace.