Open-world games benefit massively from thriving mod scenes, and while Mafia 3 is no Grand Theft Auto 5, it's seen a trickle of mods since launch. Here are a handful of good ones. Mafia III's mod scene is still pretty tiny (Mafia Mods lists 26 Mafia III mods total), but there's some solid quality of life stuff in there. Case in point:
Mafia III doesn't have fast travel, meaning that players are forced to move about on their bare wheels, like savages. For your first 30 hours or so, I actually recommend playing the game that way. New Bordeaux is a lovingly crafted homage to 1960s New Orleans, and it's worth just living in for a while. Once you've seen all the sights, though, BabaRaw's mod lets you teleport to various districts. It's not perfect, but it will save time if you're itching to go whack some racist's head in with a tire iron.
Experience the world as a bullet does, resplendent in glorious slow motion at all times, and maybe occasionally flanked by doves (but probably not). Sladernimo's mod lets you slow down time in and out of cars, which offers both a tactical advantage and also Extremely Satisfying Booms.
Mafia III's rear view mirror is a good idea, but in practice, it leaves a lot to be desired. It's ugly, distracting and, more often than not, useless. Draconio's mod makes it poof out of existence, giving you precious screen real estate to accompany all the regular real estate you've assimilated into your CRIME EMPIRE.
If Mafia III's realistic driving option still isn't real enough for you, here's another dash of complication. Budzilla's mod adds full manual transmission to cars. Confession: I, Nathan Grayson, cannot actually drive manual and am a danger to society. Also a disgrace.
Josh's mod lets you ragdoll whenever you want. Confuse randos! Play dead! Be a hoot at parties! Terrify friends and family! Probably don't try to replicate this in real life.