After having my Model S for 3 years, I thought it a good idea to replace the wiper blades even though they worked fine. Here's the advice:
1) Leave well enough alone. If your wipers work like they're supposed to, let them be (or continue reading).
2) Don't trust the wiper recommendations at an auto parts store, the book of wiper lengths is wrong for a Tesla. The correct lengths are 18" and 28", just FYI. You'll have to take the wipers back when you realize they don't fit.
3) Don't buy non-Bosch wipers at an auto parts store, they have multi-part connectors that are pretty cheap plastic and will break if you don't install them very carefully.
4) Don't buy Bosch wipers online, even at the proper lengths. The passenger wiper, even though it wipes clean, "hops" off the windshield over 70 miles per hour and makes quite a thump and a bump when wiping. This is due to the aerodynamic design of the wiper not being as good as a Bosch wiper sold by Tesla.
5) Just go to the Littleton service center and get Tesla wipers. When all the returned/wasted wiper purchases and time spent are accounted for, it's really just cheaper to get the real thing from the real store.
And thus ends my wiper story.
