Hi Jon Jones,
I can speak only as a larger vehicle owner (33 seater) - this has not really impacted me much - remember, you set a driver a target. How he achieves it is really up to him.
Matatus implement a similar *read kienyeji* airline/hotels Revenue management system. During peak, they will push up pricing and drop the rates off peak. The drivers know how to deal around this.
As an owner, only deal with the driver and my expectation is net daily (Allowance accepted for the occasional police/city council). When fuel prices are up, I gain as the net does not change. When fuel prices are down, he gains.

Even if that was possible,would Toyota Kenya have the capacity?They probably have authorized garages that can do the servicing..but then how are those garages chosen?Kujuana,competence or both?

All the very best

This might be hard to come by Believe the best way to go about it is to ask questions and those with ideas/information on the forum would assist.