All the cars for GTA 5 have not been announced yet; instead it’s up to the experts to determine which cars there are based upon what we can see on the official trailer.
Here’s IGN’s take on which vehicles they believe will be in GTA 5 based on the trailer.
Here’s another site with some information non what might be in GTA 5.
Here’s a site with some details about not just the cars, but the passenger capacities as well.
Lastly, here’s a site that shows a potentially extracted source code file with all the GTA 5 cars names. Its validity is unknown.
In GTA 5 there will be cars, planes, cops, bikes, Jet Ski’s, and more. If GTA 5 has the biggest map out of any GTA 5 game to date, it’s to be expected that there will be more vehicles than any other GTA 5 game to date as well.
It will be unknown what the official cars will be until the official release of the game. Until then all we can do is speculate about them. Once the game is released and the cars are known, this page will be updated with more accurate information, so check back after release.
Check out the "suggested by the author" links below for more GTA 5 information.