Depends on what you're referring to. If you read the Curt instructions, you need a die-grinder to shave a bit of metal off the frame (to fit a big carriage bolt into the inside of the frame). This can be concerning to some (shaving the metal off the car and painting to insure it doesn't start rusting at that spot). The bolt just barely doesn't fit. You can actually take the bolt to the bench grinder and shave just a small bit off the side of the head and it will fit without chopping up your frame (shave about 1mm off the side). I'm only going to use this for my Thule bike rack, so I wasn't worrying about shaving a tiny bit off the side of the grade 10.9 hitch bolts causing any issue with strength. I watched this video prior:I made some aluminum spacers just like came with the hitch (16:07 in the video - they're about 2.5" wide x 1/2" thick powder coated steel) out of some 2" wide x 1/8" thick aluminum I got at Home Depot (about $12 for a 36" long strip). The spacers are used to drop the stock exhaust ~1/2". With my big tips on the AWE track exhaust, I was putting the spacers in to drop the exhaust even farther (so it's not rattling on the receiver). I made 1 spacer for between the car and hitch (to keep the receiver out of the bumper), and 2 for between the hitch and exhaust spacers. I did go to the hardware store and buy replacement bolts (same but longer) to account for the added spacer length (3/8" total) which are silver in the photo below - finding 10.9 grade metric bolts in stock in the midwest wasn't the simplest...I believe they were M8x65 (stock was M8x40 if I remember correctly). Here's the finished look: I you look at the shoulder of the nut at the right side of the hitch (all gold), the outside diameter of the carriage bolt above (in the frame) is about the same size as the nut's flange. You're shaving a little less than half the distance from one edge of the nut flange's edge to the side of the nut.