New Package Cars are usually put in service according to the type of route that is run out of them. Where I am at, the newer ones go to senior drivers. Seniority is a good thing, we paid our dues a long time ago.
Our center does it based on sup's preference. Doctors notes mean nothing nor does seniority. One of our drivers hit the circle of honor last year and was promised a new car before they put his name on it. We've had 2 new 1000's come in, but he is still waiting for one.
my p1000 has 420k miles and the shelves have been rewelded and braced three ways. even the floor welds have worn through and you can see the road underneath. supposedly it's been through four engines and six trannies. but no new p1000 is gonna replace this.. this just replaced an even older p1000 last year.
Don't know about getting a new car; but I'll get a new engine. Blew that all to hell the other day ago...BOOM..then the trail of oil till it comes to rest..now the oil puddle starts. O well least I got paid to sit and wait from mechanic to bring out different car.
If something is unsafe in the vehicle, write it up.
Otherwise, its yours to keep.. well until they shift you to
another route to cover.. or if you break the one you have...
although you'd have to break it pretty good, as the mechanics
are good at getting it back on the road... in some form.