I"m pretty sure I'm ok with the clearances, there are some nearby max air vent though. Amazon has a great return policy, so that's covered. I'm on a tight schedule before the next trip, so went ahead and ordered. Will be going to Smith Mountain Lake, VA., not even sure if OTA reception is worthy there.
I'll keep in mind the Jack add-on head if things are tight. I never had a problem with the Jack, when it worked. Just always paranoid about ripping it off the roof, and the miniature coaxial they use in the mast. I'm assuming that one uses standard RG6 when installing the Jack head only?
On a non-related note, we recently bought one of those 4k Samsung curved 65" TV for the home (which is awesome!), from Amazon. Got a promotional credit to our account that more then payed for the Sensar PRO, so that was nice.