Alan answered this question on WFO radio the Tuesday after the Indy makeup weekend. If you don't already listen, you ought to. I don't miss a week. The first 20 or 30 minutes is a conversation with Alan and it is very informative.
Lex Joon's wife (Gerda, I think) had called in with the question.
Yes, this is basically an advertisement for Joe's WFO Radio show ... Tuesday night or Wednesday morning it is streaming on my iPhone during my commute. Nice change of pace, especially since we lost our 2 hour Sat a.m. drag racing show on the radio in Houston a year or so back.
If anyone else has any preferred audio content on the internet I'd love to hear it. I've tried to figure out how to get Kernan's podcasts on my iPhone but I must only have that can of patience for working on racecars ... I can't figure out how to Subscribe to get them on my iPhone.