Streamlight SL20L Patrol Car Charging

I have a few questions on installing my new light in my car. I got the SL20L with the NiMH battery.

I've already learned that leaving around the house if you leave it off the charger for a while (over a month) it discharges and goes dead.

So do you always leave this on the charger in the home?

Reference vehicle mounting....

1. Do you wire it so that the charger is always connected to power (battery of vehicle), or connected to a wired only while accessories are on?

2. In either condition, charger powered or not, do you leave your light in the charger all the time?

3. I have both the smart charger and regular DC charger. Which one would you mount in the car?

Thanks guys!!

I have the standard DC sleeve mounted in my car, and the charge connection is switched on/off with the rest of my vehicle accessories (ham radios, etc.). I drive the car really only 4-6 hours a week and that has been enough to keep the light adequately charged.
On the SL-20L the charge circuit/control is built into the switch. It will prevent over-charging.
The light is supposed to be able to take being on the charger full time according to SL, but I've toasted my car batteries by keeping a constant parasitic drain on them. . therefore I now use an accessory switch. Looks like they don't recommend continuous charge if environment is below 10 deg F.
Hope this helps.