Just run them up to operating temp once every month or two keeps everything fresh. I have an old plow truck that I added a battery disconnect to because of parasitic drain over time. That's going to get sold one of these days. I'm a stickler for maintenance. The vehicles that don't get driven a lot never seem to need new parts for years at a time. I get something new to me and I go through it, fix everything that needs it, full tune up with fresh iridiums if the plugs are worn or due per maintenance schedule, oil change w/filter, cabin and air filters, grease the zerks, new fluid in the front and rear diff, transfer, transmission fluid and filter if applicable, power steering fluid, brake fluid if it's dark, coolant if it tests out badly. After all that Inhave established a baseline ... everything is fresh and inspected. It's usually good for a long time until brakes, oil change, air filter need changing ... all easy stuff. If an occasional high dollar repair is needed, it's not a shocker because I don't have any car payments.