Hiya
A group buy has just finished on the Aero side skirts (although some ordered the full kit at discount) so I don't think there will be another one for a while.
If you're willing to take on the responsibility yourself you could start one in a few months time maybe?
Group buys can save a lot of money if there is enough demand and a willing dealership
I would suggest leaving it a while then starting an "interest" thread to guage how many people are considering it.
But be warned, not all members who sign up will be forthcoming with the cash when it all goes ahead. We recently had over 100 signed as interested for the aero skirts, about 65 of them confirmed themselves as definites, but when it came to it quite a few bailed out (for various reasons).