Where can I find widebody kits?

I don't know where you heard that but its not true. Wide body kits can't be bought in the stores at all.
They are an exclusive mod that can only be obtained as a gift by beating the random tuners that appear on the
streets in what they call "outrun challenges." Usually you will only get cash, but occasionally you will be offered
an exclusive part for free. They can be anything from vinals to engine upgrades and even wide body kits. They are
always something unique that can't be bought. However, after level 5 wide body kits and unique vinals become
available in free race and arcade modes. In career mode you have to earn them.

What you do is just beat the game and you get the entire set of wide body kits. If you cant get to stage 5 then I can help because I've beaten the game. Just tell me why you cant get to stage 5.