I want to put on an si wing on my ex however i have the factory lip installed. My question is are the drilled holes in the trunk the same for both wings or am i gonna have to drill new holes?

 

yes there are already holes from the lip spoiler
can't remember how many.. 6 or something?
and you'll need to fill those up and paint it or just use some sort of plugs

then you'll need to drill new holes for the Si spoiler

 

Theres a few members on here that have both wings on there. Check the picture thread.

 

you could just swap your whole trunk lid.