I saw it in London with Michael Ball and really enjoyed myself ( came out of the theatre with the biggest grin on my face, humming "bang, bang, chitty chitty bang bang ").
I have tickets to see the Broadway production in May.
The audience will not just be kids and their parents ...but also those who grew up with the movie ( my niece, now a working professional in NYC, has also gotten tickets for herself and her husband - after all, she still knows all the songs by heart from childhood

). It will also be an attraction for many tourists who are familiar with the movie.
Btw, there is a Region 2 DVD of the Making of CHITTY based on the production at the Palladium in London. It has five full production numbers from the show.