#17 Fix bad weatherstripping immediately
If your weatherstripping is letting rainwater leak into the interior of your car, take a look at it and decide if you can repair it or if it needs to be replaced. Small leaks can be handled with brush-on seam sealers. Resecure loose sections, not otherwise damaged, with trim adhesive. Torn sections may be repaired with special caulking available at auto parts stores. You may also be able to extend the life of worn-but-intact sections by inserting foam rods, available at automotive stores, into the hollow section of the weatherstripping. If you decide to replace entire sections of gasket, don’t simply buy generic stuff such as you’d use around the house. Buy a product that matches your car’s original weatherstripping—it’s available in a wide variety of profiles from dealerships and automotive mail-order catalogs.