I switched from CR123 lights to AA lights running L91 cells in my trucks a couple years ago. No real reason other than I prefer a little larger form factor in my vehicles (easier to find, harder to lose, etc). Running a 5.11 XBT A6 in one truck which I am EXTREMELY happy with. Runs two parallel stacks of 3AA cells so it can run either 6AA or 3AA plus gobs of throw. I have a Coast HP14 in the other which is OK but I wouldn’t re-purchase. Not as bright as others out there, goofy zoomie head and worst yet the switch has been somewhat unreliable.

Since you are talking about CR123 lights I’ll tell you what I have run in the past and thats Surefire G2 lights. I actually really liked the old G2 incan I had in my glovebox for years. Surely those 65 lumens were Surefire lumens because the bang thing never let me down! I also have a G2L-FY which has the 120lm head. Obviously dated but they were both great in their day. I do like the 2-mode (Police model?) G2X I have that starts on high with a clicky tailcap.

If I was going to put a modern CR123 light in the truck it would be something like the Streamlight Polytac HP or the Lumensfactory Seraph 9 with or without Turbo head. I have a 3-cell Streamlight Protac iHL 3 in the gun cabinet which would be ideal as well. Right now I’m looking to buy or build a 4-cr123 compatible p60 module to use in a old Cabelas XPG host; just not sure how hard I can push it in the plastic host.

My goals with a truck light is to be able to spot addresses, scope out camping sites in state forests and other longer range tasks. It also has to have longer runtime options to allow for emergency use in roadside repair or other extended situations. Wonderful age in lighting, today. Many, many top notch options!

EDIT: I didn’t think of this until now, but when I paid-on-call fire I carried my Streamlight Survivor (LED) on my turn outs and used it often when working downed lines and such. Not the highest lumens compared to other lights but great LUX. Very useful that you could leave it on the 12v charging cradle, though that would be less useful for many people.