Well, today I just put a permanent grill block on my Green Bean. It's quite simple, but yet effective. I cut out a 2.5" X 6" rectangle and put a flap that I can open and close with a very strong fishing line that runs through some eyelets and into my cabin space next to my fuel cut off switch. It's held on the top by HVAC Silver aluminum tape (about 3 layers for durability) and at the bottom by 3 mangets. The string pulls it away at the bottom when I pull on it. It takes a bit of force, but not too bad when the car is not moving, but much easier when moving down the road. At 50 mph it still held closed on it's own, so I'd say I have the correct number of magnets to do the job.
Gravity will close it at a stop if I let up on the string, which is held by a hook on the interior.This should help with warm ups a bit more. I also just put LED lights for the exterior lights except for the headlights. I'll order the LED headlights today. Planning on Alternator belt delete and using a flexible 100 watt solar panel on the roof this summer.