The Tranzformer by J3 Competition. This stand allowed me to have all the utility of a built in work surface in my race trailer without installing a permanent workbench. Roll it out and have your bench next to your kart. And your trailer is easier to sell as it remains a standard utility trailer or car hauler.
Extraordinarily well engineered. Very heavy duty. With kart hooks (silver items on floor in photos) installed, two karts can be loaded and transported horizontally – one on each side. Includes all accessories – sprocket holder, wrench holder, trash can, laptop tray (light gray in photo), helmet tray, upper shelf with two paper towel holders. It also has holes to hold 4 50mm axles. Two heavy duty swivel locking casters and two fixed casters. Small vice (not a Tranzformer standard accessory) is also included. $650 obo. Located outside Rochester, NY.
See it here – http://www.ebay.com/itm/Tranzformer-Kart-Work-Stand-/252707705866?hash=item3ad68d940a:g:9a0AAOSwopRYawhd&vxp=mtr