When I got mine through CarID I expected to have to drill it so I was ringing up the local body shops while the spoiler was in transit, but when I got it it didn't have any screws in the box. So I called CarID and spoke to a technical rep and he stated just to use the 3M tape that's on it, and apply a few dobs of silicon adhesive and it will stay forever. He went on to say this is what they do at the dealers as well, and only if a customer is adamant that it be screwed down they just do the peel and stick.
FYI - I had them paint mine to my body color and it matches perfectly. Took a few more days to get it, but well worth the extra $100 to not have to mess with the body shop.
As far as installing, took me all of 15 minutes and most of that time was just measuring about 5 times to make sure the spacing was exact.

Enjoy whichever way you go, it's an awesome look to clean up the rear trunk line.

 

What front lip is this? It looks really good.