I'm getting the skin/cloth overlap. What i'm doing wrong? I'm making a GTA style game (I KNOW IS IMPOSSIBLE TO MAKE A GTA BY MYSELF, BUT HEY, I'M YOUNG, HAVE NO FRIENDS, NO GIRLFRINED, WHY NOT SPEND MY FREE TIME DOING WHAT I LIKE THE MOST? :D) and i have a character that constantly change clothes via Menu, what i want is to attach a police uniform (SWAT like) to my character, all animations are done perfectly, until is time to make the Aiming animation, when i do AIMING animationS the skin overlaps the SWAT uniform as you can see on the screenshot


This is the normal aim, frankly, you don't want to see the Top aim animation LOL

I tried everything, weight transfer, data transfer modifier, automatic weight (instead, this is the best i can get, automatic weighting) and i don't want to use alfa mask, becasue the character will be changing clothes during the game and believe me, THERE IS NO TUTORIAL ON HOW TO CHANGE ALPHAS FOR DIFFERENT CLOTHES FOR UNREAL ENGINE 4, ALL INTERNET, NO LUCK, so, alpha is not an option, i ask on all Unreal forums, no answer, search on youtube, no tutorial. How does game modelers animate a clothed character (with changeable clothes)??

I don't know where else to ask, hope you guys can give me a hand, i'll name you on the game credits as helpers!!! I just attached the .BLEND so you guys can check what's wrong with my model.

Here's the blend file
https://mega.nz/#!WFNG0ICY!caklH2v5fP4gSYQNiz-MWpTLibcXXanng2nUMGP90Qs
You are most likely getting this problem because the body and the clothes have different topology and weight values for deformation. Open the clothes in weight paint mode, then add weight on parts where the body is sticking out.