Well I'm glad to say my son and I had the exact opposite experience to the OP on Sunday. I took my 5yr old with me to my local club and asked if he could drive around during practice and between races if we had a suitable gap. The race director gladly said yes and turned down my offer to pay for him.
During the day a number of members including the race director said a few words of encouragement to my son and he thoroughly enjoyed himself. I now intend to give him more practice (mostly outside club meets) and then try him racing next Summer - aged 6.
It probably helps that he isn't a full-throttle kid, but nobody knew that until they have him a go.
Longer term, not only will the club gain a new member, but they'll make it easier for me to integrate my hobby into my family life - ergo, I'll stay around too.
