Hi Dog Chevy, I can't say if the 08 to 12 Spanish builds are the same, but I did fit a genuine alloy bar to my 2012 ST so I know how that works.
My advice, remove the bumper all together and see of the bar fits, that way you won't be cutting the bumper in half to realise it doesn't work.
If it works, measure the distance from where the bumper joins the front guard down to the bullbar. There should be a cutout at the top on the inside of the bar for the bumper to pass through. As per the pic, I cut mine as low as I could to have the bumper at the bottom of the cutout. Once you get that measurement, mark both ends of the bar and run some masking tape from one side to the other with the bottom edge of the tape on the marks. This will protect the paint above the mark and act as a guide to cut. I then cut it with a jigsaw. I found it better with the bumper off as there are some bits of mesh and stuff behind the bar that the jigsaw blade wasn't long enough to cut through.
Once it's cut, fit the bumper then fit the bullbar. You'll need to trim the front of the inner guards afterwards, i did mine with a stanley knife while on the car
Hope this helps, if you need anymore info, let me know
Brett