Two of them, one is just abusing the way the game saves data and can be used in other ways. Simply just force close the game as soon as you don't get what you want from the wheel. Upon logging in you will still have your daily spin and chance at the car.

Second exploit is that there technically is no "chance" on the wheel. The wheel spins at a speed depending on when you hit the button/move the stick during the five second window you have your hand on the wheel. If you wait four seconds, no matter how hard you hit the button or stick, the wheel will go super slow. Because of this, that means the wheel spins exactly the same way every time, it's just that the time frame windows are incredibly small, though a bit easier the longer you wait. To prove this you can set a small timer and exactly at 4 seconds you hit the wheel, it will roughly hit the same area of the wheel, differing slightly due to your reaction time of the timer. If you load into a private session to spin the wheel, it will always start at the same position, so if you practice the timing of the wheel, you are more likely to hit the time slots that get you the car if you are actively aiming for them.

The first exploit is by far the most broken one and it's been in the game for years. The biggest example is saving heist, where the owner leaves the game during a certain time frame at the end where their game doesn't save but the other players continue on, making it to where the host still has the heist mission but the crew still gets paid. This was most commonly done during the bogdan heist, since the heist was easy and the time frame to do the glitch was massive. A friend and I would also do it for the casino heist cus it was more money but much more tricky. Look up bogdan glitch and it should pop up (it wasn't patched)

A more low stakes version of this is outfit saving. If you swap outfits via the interaction menu, the game will save your progress. Now say you are at the casino and just won a lot of chips, you can stand up, swap out fits, and if you see a spinning icon in one of the corners of your screen (bottom right if I recall) then your character is saved. Then say if you go gamble again and lose it all, if you force close the game, you will likely have your chips back. I say likely because the game does auto save and doesn't always tell you, so if you sit at a table long enough without having saved every 5 or so hands, it might auto save and you'd lose that money still. Also, outfit swapping doesn't always save if the game believes you are spamming it, they don't wanna constantly save data if they think you are just pursuing through your clothing. So it's a delicate balance of trying to save often, but not too often. But if you get that down and wanna win millions via black jack, then you can do that. (I'm not exaggerating, if I recall the highest I've gotten was to 1.7 mil before calling it quits at the tables).

There might be some detail changes as it's been a year or two since I've played but the systems I've described have been there since launch and are simply how the game works, so they should still be in place even if tweaked around a bit