I personally today would much rather watch a new episode of Fifth Gear to Top Gear or Amazon's GT. Before moving to TG, Chris Harris on Cars was epic and for me the best Youtube based car reviewer.
I possibly also would buy a car on the strength of a few car reviews, ie long term test showing the real world performance, cost of ownership, reliability. Who wants to buy an unreliable sports car? and how do potential buyers gain information generally about a cars reliability? from reviews. Ever looked at a buyers guide before going to view a car? that's review.