Side Skirt Falling Off

Its quite a common fault on the ST, if as you said you have tried double sided tape and it didnt work , drop Wolfman a PM as i know he uses some kind of silicone based adhesive designed for fitting body kits etc

I had the same problem and had to scrape away the crappy double sided tape and use tiger seal to stick it down. Had to prop slabs against it to hold it tight but after a few hours it was stuck fast!! Just be careful with the gun thing as I got sme of it on the body work.....it's ok though as it's powery whn dry and will come f with a good wash and scrub.

I got a tube on ebay for about £7.

I spent 2 hours doing this last night.... worst part was getting all the old stuff off (and extra stuff that ive added in the past to hold it).
I used double sided tape and some sealant/adhesive where possible.... Problem is, the tape isnt making contact with the car in a lot of areas so the skirt does move slightly, but that wont be a problem i dont think.
Looks straight now, and its tight to the body along the top edges so im happy..