Installing a Harman 52i in new construction in a zero clearance cabinet. Asked the dealer when I bought the box if there were other installation parts I would need. Said no. Didnt realize it was "just a box". Went back today and they sold me the fresh air kit and the exhaust kit. Back home and nowhere to mount the kit parts. Do I need to buy the mounting bracket too? Dealer didn't provide suggestion to buy the mounting bracket although I described my installation. Cant find much info in the googleverse. Found a few illustrations. Harman instructions contain minimal info.