A good windshield seal should be on everyone's "Vanagon improvement" top ten list. Keep the rain out and your feet dry, as well as stopping rust in that notorious Vanagon rust area. In addition, you will be stopping water from dripping on your fuse block and thereby avoiding a whole host of electrical gremlins. A nice, new, non-crusty seal looks great, too!
Available from USA or German manufacturer.
Note: Unlike other window seals, this one has the seam on top. This does not effect fitment at all, but it may differ in appearance from your original seal.
Additional Note: This seal comes without a groove for the now-obsolete chrome molding. Unless you plan to reuse your scrappy old molding, you'll want this grooveless seal.