How big is this intercooler?

Two options that are preferable to nothing at all are:

Cut out the section of the front bumper (what you're calling the impact bar) that impedes mounting the intercooler. Depending on the size of your intercooler, this will leave you with either a small or very small section of the front bumper on each side of the intercooler, and thus a few bolt holes to which you can mount the bumper cover. Also, you might want to keep the thin upper metal strip to for support. You put the bolt through there where there is a bumper to bolt into, and then you can zip tie the remaining holes (strap and bumper cover).

There is also a bumper replacement made from aluminum (I think) that is specifically designed for this application; that is, for DSMs with small to large (not too large) front mount intercoolers. Do a search, though.