Interesting questions...

I would think that trading cars may be feasible, but would I give up a Mercedes? That is very difficult to say as a 5 year old Toyota is probably worth 20% of a new base model Mercedes. In all reality and based on the scenario of an interstate highway, any vehicle is not going to get very far due to all the other traffic now backed up all around you. At this point, I would find the closest and hopefully safest spot to park the car and start looking for alternate transport even if that meant a very long, difficult multi-day walk...however that rules out getting home asap. Something to ponder over and see what others here think.