That's actually a good question because I have no idea. Another member on the forum signed up for the guarantee I was sent last weekend, but never reported whether or not it worked.
If it is possible to sign up for someone else's guarantee it'll probably be a short lived event as Uber will catch on and start figuring out a way to make people stick to the guarantees they initially receive.
A forum community dedicated to Uber drivers and enthusiasts. Come join the discussion about taxes, documents, visas, travel, car care, finances, banking, maintenance, reviews, accessories, classifieds, and more!