Vikki, mine run through the X-brace as well.

The one thing about running the piped through the tunnel like the original is it does throw extra heat into the passenger compartment. My kids have mentioned a couple of times that the seat belt bolts for the front seats can get pretty hot. Not enough to burn you, but definitely hot enough you will not leave your hand on one.

Never had any rattles with the exhaust but I did have to loosen a couple of clamps and put a block of wood on one of the mufflers and lift with a jack. That was just to tweak it enough to get both sides to look the same in its normal stance.