I wanna know is it still count as 100% completion if I blow up 2 other car on that one mission with 3 car I need dump in to the see.

probably not, since you need to complete all the missions, if there was a category called "All Missions" or "All Story Missions" then yes, you could potentially do that, but I don't think it would count as 100%, let me know if I'm wrong :)

In 100%, you need to complete all of the standard missions that you get marked on the map from the payphones.

yes, but doing that technically wouldn't count as a mission completion, which means you wouldn't get proper 100%, and what I was trying to say is, All Missions would probably allow that since it doesn't require to finish the level 100%, this is just a big assumption tho. (do add All Missions as a category tho) :)

As I saw thats only +2 bonus missions but I don't sure (a play only payback campain a wihle ago, and only few days in strory mode), so thats is just a little bit longer. If someone really want to do that, someone have at least make a guide where a new player can find this bonus missions.

It's not hard to find, but if you want, sure, I can make a GUIDE, for finding TWO missions that are VERY CLOSE to each other, sure