I've noticed the lack of tutorials for the Minecart skip, so i did one myself. Recorded on my PS4 with clips and i don't know how to add my voice so i did it all text in the description. (that i'll put back here after the video link) here's the demonstration on video with a consistant way of doing it :

Description: The Minecart Skip has two ways of doing it, one way only works on PC Version, and there is this way. It is not that easy to master, but this works on every versions (I know it works on PS2 at least.) For this to work, Leon has to face the left side while being on the bottom right corner of the second minecart, you next have to wait until the [JUMP OVER] button dissapear. From there you just walk a litlle bit backwards until it reappears and press it, and you should be good (Don't hold forward or Leon is not gonna clip through.) You also have to be on the Striker/Ditman Glitch. The weapon does not matter.

Edit: You next have to go back, pass in the floor , on the left to the barrels , and then you can just run out of bounds, follow the railway to go down and finish the area.

Striker/Ditman Glitch : When you aim with the Striker before the laser shows up, Leon's animations goes faster, and you can keep that speedboost by changing weapon while aiming before the laser shows up. Lestaku-senpai.