Yup, I used the spacers that Infinity supplied with the speakers. In fact, if there is anyone who wants to install 6x9s in the doors of their "Contiqueo," here is my advice in three words: Use the spacers.

Otherwise, you will have major problems in getting your windows down.
From what I read in the
Car Audio forum, it is advisable to get 6x9 speakers that have removable spacers (such as the Infinity Kappas).
Yup, I did have to drill new holes (with the windows up). It may sound gruesome, but it isn't. I used a 1/8" drill bit on my Black & Decker cordless screwdriver(!) to drill the holes (again, with the windows
up); then, I used the screws that were supplied with the speakers to mount them.
I give this job a "moderate" level of difficulty. It's not the easiest, but it isn't difficult. Patience is required though.

One more thing: You will need to trim the metal bracket for the door handle pull on the rear doors.