It may seem like overkill, but a tempered glass screen protector is cheap insurance for the 15" screen in the Model 3. It will protect it from scratches and impacts from all sorts of possible hazards like phones being put in the dock, drink bottles, or wayward jewelry.
Abstract Ocean is a very popular choice because of their reputation for quality and customer support, but after comparing it to some lower-cost options, the screen protectors appear to be identical with the same fit and they come in very similar packaging.
Also interesting is that most of the lower-cost screen protectors from different sellers under various names are actually branded as Glass Screen Pro. Thankfully, that's not a bad thing since the Glass Screen Pro screen protectors are good quality with a pretty good fit. The corners are not perfect, but the bottom has the proper curve and the sides and top fit great. Just make sure you install it right-side up (which seems to be an issue for some).
While it's still more expensive than the competition, Abstact Ocean has recently dropped the price of their protector, so theirs may be a convenient add-on to your order and you can use code LIVINGTESLA for 15% off to get it even closer.
Otherwise, check out any of the options that we've verified are Glass Screen Pro on Amazon.