Need Help with Car Textures

I am trying to make a rollercoaster with the cars looking like they are made of crystal, yet I have no way of editing the texture exept Paint which screws up the texture.

Help please.

^ i would do it but i don't know how to mask the texture correcly on the car cause i have photo shop. but sorry tho.

MS Paint dosn't support alpha textures, im sure a kind member would do it.
I would cpt im in the office.