I just received Z roadster spoiler from spoilerdepot. But no instructions.
Can someone tell me what I need to do to prep the surface before installing the spoiler?

 

Here is 3m's Automotive Adhesive webpage,

http://solutions.3m.com/wps/portal/3.../Applications/

make sure your surface is clean, i'd probably remove the wax by washing the area with dish soap... i think there is a surface spray / wipe i think 3m uses, but also if u use alcohol pads to pre wipe the surface, let air dry, then attach the 3m tape, you should be ok...