Source google image: http://img.wonderhowto.com/img/79/77/63410931746984/0/working-lego-roller-coaster-by-matt.w654.jpg
Lego instructions roller coaster
Source google image: http://img.wonderhowto.com/img/79/77/63410931746984/0/working-lego-roller-coaster-by-matt.w654.jpg