Osborne House often hosts classic car rallies in their car park - last time I was there last year there was an amazing gathering of some 50 classic Jags, some of which I had forgotten were even built!
I suppose it does involve a tour of the House, but it is well worth it.
As for IOW being 'reserved', you might want to reconsider that during Cowes week, or any Saturday night in Ryde.
But yes, it is a beautifully unspoiled snapshot of the past and long shall it remain so.
PS check your ride heights on the new Lymington/Yarmouth Ferry ramps... `