MK2 Mexico front spoiler fitment

Hi Folks.
 
I started messing about with a fibreglass front spoiler today to see how best to fit it.  It's early days, not having drilled a single hole anywhere yet, but it appears that the (flat) bottom edge of the spoiler sits marginally higher than the bottom lip of the front panel. Is this normal?  I always assumed it would be lower.
 
I'm still thinking about how best to go about fitting it, so recommendations (especially photos) would be welcome.
 
Thanks.