fix for the chrome talipipes
I had the same issue, and i ended up driving around for a few days with the tips on about 3/4 of the way in. Even with a rubber mallet they felt like they didn't want to go in any further.
A few days later, after a driving one day about (15-20 mins after) I thought I'd try again - The tips were a heated from the drive and the slide right down with minimal "help" from the mallet.
heat them up, or try it after a drive. I know the exhaust pipes will probably be expanded too, but my tips just slid on.