Having almost completed all of the Exclusive Series (Nissan, BMW, Ariel, Ferrari)  I have the following observations and opinions about it.

• I like that I can earn more GC.
• I like that there are more events to race.
• I like that there is a full series of races exclusively for each car.
• The previous point--combined with the extended durability--allows me to become more familiar with a particular car.

But:

• The rewards are meager.
• There are no long races.

Lastly:

• Some opponents are driving cars other than the exclusive car, which means that the series is not exclusive, except for the car that I can drive. Thus, instead of it being a competition amongst equal cars, it is a competition against a variety of cars, some of which are equal and some of which are not.

• Will the next batch of exclusive cars consist of a selection of the cars against which we are racing in the current ES? For example, Ford Focus, Aston Martin DB9, Lotus 3-Eleven, McLaren P1? And if that is the case, will it be tied to the current series?