If like me you don't like velcro straps to hold your lipo's down then here is something I made in ten minutes, mine is a 2s setup but I can't see why this won't work on a 1s setup too.
All you need is a 1 degree camber strap with the outside holes drilled to 5mm (the 2 degree camber strap is too short) and two Cougar SV2 top deck posts shimmed up to whatever the thickness your lipo's are, there is no drilling on the chassis to do as the posts just replaces the nuts either side that hold the battery nest down
http://s19.postimage.org/ovqtqbgcy/IMG_1779.jpg
http://s19.postimage.org/6hgamc42a/IMG_1780.jpg