Originally Posted by Diseasel300

It's a good idea to use a silicone based grease on the window slides and tracks. Lithium or petroleum greases will turn gooey when exposed to moisture and will harden over time. The silicone grease is non-reactive with water and does not become gooey with age. Over time it will dry out, but will leave a slippery silicone lubrication layer behind.

Sunroof grease is a good choice if you have some handy. If not, get some water faucet grease from Home Depot. A little pot goes a long way, that stuff is slick! Basically the same stuff as sunroof grease, but slightly heavier in weight.