The consensus is that these Trac-Grabber traction blocks work terrific for some people and lousy for others. Level of success seems to be based on: type of car; usage scenario; and user skill and experience with getting a car unstuck, and driving in general. But no one really admits that last one. For example, one dude Trac-Grabbed a lady in Edmonton who'd gotten her compact car lodged both in snow and high centered on a sidewalk. He said it took some finesse and about 90 seconds, but the strap-on blocks worked great. A 1-star review from a Mustang owner was less impressed; he said instead of improving his situation the Trac-Grabbers seemed to dig holes in the snowy road and get him more stuck.
Trac-Grabbers also advertise themselves as solutions to freeing vehicles from sand and mud traps, but low reviewer ratings in those areas suggest the tools are better suited for the evil that falls from the sky rather than that spewed up by the earth.
Each Trac-Grabber package includes a pair of 8" long x 3" wide x 1" deep blocks threaded onto an adjustable canvas strap that "both men and women" (!) can secure to their tires with ease. Once in place, Trac-Grabbers take hold as the vehicle's wheels start to spin, and then lift, grab, and help move it to more stable terrain. The Trac-Grabbers here were designed for use on cars, vans, and ATVs. Trac-Grabber also makes their "Get Unstuck" tools for trucks and SUVs.