What are readers really looking for when they purchase a buyer's guide?

How much faith does the reader place upon the author when using one of these guides to actually purchase a car or motorbike?

Readers want the experience of a real marque/model expert to guide them to a safe purchase. They want the advice of someone who is familiar with the most common problems associated with the model and someone who knows the real cost of repairs/renovations.
Readers also want to ubderstand the diffrences between various versions of the subject vehicle and relative values.
Lastly readers want to purchase knowledge at a sensible price in relation to the cost of the vehicle.

Regarding the amount of faith readers put in the book's advice only a reader could say, but I hope it is a lot of faith because our marque experts are carefully chosen.

I was not asking the publisher for any answers. I was attempting to generate a discussion amongst the forum readers and users to get their opinions.
I am interested in what the readers want and perceive.
It's the readers that write the reviews.