I gotta say, I have decided not to buy FH5 and pirate it so that I could use cheat menus worry-free and it feels so good not to have to worry about these limited-time FOMO-inducing specials. You just tick a box and poof! you can buy it.
Also, I actually enjoy building cars more than driving them.
There is an option to add them to the autoshow. Basically you tick a box and then they they appear there, ready to be bought.