I just bought a 13 850xp and am looking at getting the last of my to do list done on it. First question is I bought some grip and thumb warmer from Polaris for it and wondering if there is any tips or tricks on installing these? I read the instructions and it all seems pretty straight forward. I use symtec's on my canam but the dealer said they have had good luck with factory ones so I thought I would give them a shot. 2nd question is what kind of muffler are you guys running? I heard hot seat but where's the best place to buy from maybe a sponsor on here? I use a hmf on my canam and it sounds sweet.