Nope they are 'plug and play' as it were. The problem with them kicking in late is well known but sadly just a part of them, they kick in too early at low speeds, or at least they would if they were set up to kick in right at 100mph. As for the skirted ones, hmmm not sure at all, they always work for me. Are you using 04 or 06?
Andy
I wish that you could choose when they kick in with triggers then you wont have to set the speed to round about 40.