I have always felt that you hire an consultant to correct a problem or improve that department. What you sometimes get is a system and some nice reports on how effective and profitable it will be if everyone follows their plan. The bigger the fees and the bigger the name make make you think the better the service, not always the case. Their references are mostly word of mouth from dealer to dealer. The problem with references is that most dealers find it hard to admit that they made a mistake in hiring that particular consultant, so who can you trust. I don't have that answer but I have ideas.
I have been brought into several dealers to solve problems or help them expand their facilities. I am no super manager but I do know what normally works, based on the size and location of the dealership. I normally find that the people in position are quite capable and got off track by some manager in the past or some long forgotten system that was being used.
I am from the "old school" in that I treat the customer fairly with regard to pricing and content of service. With that in mind it is not unusual for me to achieve department sale increases of 38% , department gross profit increases of 32% and departmental profit increases (line 30) of 44%. Remember that the Parts department tags along with similar increases. I actually lowered prices, raised labor rates to just below area levels, disbanded "teams system", and everyone made more money which improved production and attitudes. The friendly treatment and reasonable pricing brings high TSS scores and loyal customers.
Most managers feel threatened or embarrassed that someone is coming in to "help" them. They withdraw and make that person prove themselves and in general the whole process of improvement is delayed, until acceptance is established. The big guys in the business, ATcon, Dealer Services and others, in my opinion are using ten year old ideas presented with new wrapping with lots of complicated systems that makes the dealer feel good about his decision. The test is how well things are improving with your fixed operations. If the consultants are not reaching the levels of improvement I have stated above then you should be asking why not.
If as a Dealer principal or Service manager you feel that your Toyota service department could use some help, or just want a second opinion for some ideas let me know if I can help. Feel free to contact me firstname.lastname@example.org.