Lots of little things that don't make sense in this game. Why have honking if no one pays attention to your horn? They sound fake anyway. Why have wardrobes if it's just the same outfit with different colors and patterns? Why show other styles of clothing on the store racks and shelves if you can't buy them? Why would a guy trying to conceal his identity even walk into a clothing store when he can anonymously buy stuff online?
I can come up with tons more, but the most appalling thing is the horrible performance and scaling. Especially the driving.
Also, the bit with others being able to hack into your game is not clearly defined. I was assuming I wouldn't even see anything like that playing sp, but it happened anyway, and the game never made it clear if it was an "online" character AI from the game world, or an actual online person. At any rate they definitely try and shove the Online Hacking mode in your face even in sp, with a forced segment early on dealing with it.
As it turns out, I found you can easily go into the Online part of the menu and disable "Online hacking", but this is something they definitely don't warn you about, so be advised if you don't want it, turn it off. Previously I even went to the extreme of disabling my LAN connection to make sure no one could hack into my game.
It's also very quirky how they structured Online Hacking mode. As others have said, they make you believe your sp game is deadlocked until you participate in this online hack duel intro mission, but as it turns out, you can just leave the mission then come back, and then the game reverts back to how it was before the hack invasion.
It's as if they rushed this Online hack mode and never decided how to implement it in sp. Either that or the tutorial for it is too vague to understand.
.. The rain\water effects are good but again not finished as you or ai disturb the water 
