Interesting array of opinions and thoughts, so thanks for them.
I actually did a poll of a similar topic on Twitter yesterday, asking if people thought "jet trucks, aircraft vs car races and related activities have a place at airshows today." 65% of responses were against these 'side attractions', but it should be remembered that most of the people completing the survey were likely enthusiasts. However there was also discussion that such diversification sometimes enhance events and flying displays.
Actually my final year project at university (AKA Dissertation) which I am currently writing the proposal for will tackle this issue and the state of the UK airshow industry as a whole but that's a different topic... The whole team at RAF Cosford remain dedicated to delivering the Midland's premier aviation event and whilst I agree attracting rare and exciting aircraft to the show is essential to this, we must also remain open minded to provide enjoyment for all the family and keep innovating in the entertainment side of airshows.
Back on topic;
there will be more details about the RAF Cosford Air Show 2016 announced in the next few weeks so keep your eyes peeled!