[m2speed]

I have an excel spreadsheet for calculating top speeds and gearing selections for a Miata. I would like to use it on my Boxster but on of the things I need is the drag coefficient. I really would like to know it for the stock Boxster with top up, top down and hard top. Also any mods know to low the coefficient like different front end and lowering the cars overall effect.
I would like to post the spreadsheet for others to use but this site wont except it as an attachment.

Jeff