I've got a couple of Kubota's that have been to the dealer for repairs. They say up front - first come, first serve. And the "first come" doesn't start until the tractor is in their shop Which seems a terrible way to run a business. A tractor can need service but still get work done. But the dealership takes it out of service by requiring it be in their shop in order to get in line for repairs. I tell them, when I bring the tractor in, that I know their policy. That my tractor is from a working farm, and I need it back speedily, to make money, to pay them. I do it lightly, nicely, but in a businesslike manner. There's no agreement, but I get the tractors back sooner than they indicate on the phone, when I call in to learn waiting time.
There is no issue getting parts from Kubota. They ship next day, and dealer gets the parts two days later (UPS service standard from Georgia).