Got a truck?
Got a bike?
Need a way to transport your bike on your truck?
I got this idea from a local bike shop. It's pretty simple and pretty cheap too. I could easily see this modified to mount bikes inside a mini-van by using a piece a plywood instead of the 2x6 for a sturdy platorm to keep the bikes stable.
Cut a 2x6 piece of pressure treated wood to fit in the bed of your truck. Most truck beds have a built-in slot to hold the piece of wood.