The reason for the error message is because you now have an object without mobilephysics, but that still has all the physic elements like springs (which define where, how much and when the vehicle has friction with ground) attached. This apparently causes BF42 to go into lockdown, as it's pretty impossible to calculate physical parameters with an object you define to ignore physics
. Would be the same if you tried to attach springs to a building...
To make this work you would have to removetemplate all the physic elements too, I fear...
But first, try holdobject 1 in the correct place. As long as nobody seriously bumps the wreck, it should stay immobile. Ramming it with vehicles or heavy weapons will probably initiate the jittering again...