I will be interested to see how they make this work... I could see how they could make some interesting team challenges with this amount of hosts. However, I'm not sure how it will work when they are just "reviewing" cars.
It will also be interesting to see how they review cars (i.e. not just do weird automotive challenges). The previous hosts were not as detailed as some of these new ones will want to be...
For me, I'd be happy with just the following hosts: Chris Evans, Rory Reid and Chris Harris. I think for a TV show, those would make the most sense.