that initially looks like the shock would just move forward when the motion starts, but that might just be crazy enough to work...if you make a rough free body diagram of the system it seems to work out- the forces are definately opposing on either end of the shock. the angles are a little goofy on that bottom section probably, which messes with ur head i think.

what if the shock was somehow fixed in place?

Just my $.02! i could be miles away though!