if you mean notched, a decent looking notch shouldn't be hard to do. i'd be somewhat interested in that myself, as with notching you'd only be cutting through a little plastic. i believe bmxcontour (from ohio) notched his rear bumper. probably wouldn't be too difficult. now if you want an actual cutout, that'd be a little tougher.
No car anymore ;\ (taking a break from driving due to several misfortunate occurances)
Newest mod for my Dad's Cobra 'vert: My beautiful girlfriend and I for passengers when we want to go somewhere