2 ways to get a tnt cart off a track without detonating

Way 1: Placing a tnt cart on a rail, then destroying the rail makes it stay where it is. Pushing it around does not make it explode.
Way 2: By pushing it through a block with this setup:
https://www.dropbox.com/s/u7w2ni3nfpls35c/2013-02-15_00.11.07.png
Just place a tnt cart on the diagonal rail, wait a second and place another 1.
Then wait untill the second cart pushes the first one all the way through the block and you can start pushing it around.