These videos covering lap times and top speeds of every vehicle in GTA Online, as well as this document made by myself, will all be used to reach these conclusions. There will be a heavy leaning towards cars that will allow you to compete in races and be quick in free roam, alongside more useful vehicles for missions and heists.
This article will order things by importance, with the most useful cars first. In most cases, doubling that first cool million is going to take some time, but it’s also not outside the realms of what most people will be able to achieve through a normal experience with the game. However that does require the entirety of those 4-5 hours being spent grinding money rather than doing other more fun activities, and you need to have invested in certain businesses already to reach that hourly income. If you’ve already invested heavily in the game and put all your effort into grinding money in the most efficient way possible, you could earn this in about 4-5 hours as we explored in my previous article on how to make money in GTA Online. For the purposes of this discussion I'm going to set a hard limit of two million GTA dollars.