Well I went to your web site I'm sorry to say I didn't find the pic. So I'll give you my thoughts on this. Yes the roof is the best place for a Ant. And it's where I was going to put mine but the thought of a low tree branch bending or breaking a 40 to 70 $ Ant. dosen't sit well with me. A 102in Whip Ant. can be just that a WHIP to anyone standing by your truck while you go by, Which is why alot of clubs don't want them on the trail. I use a ball mount with a 5ft fiberglass Ant. with 18ft of coaxial cable. The big reason for me to go this way is my Blazer had a hole already for a ball mount, It's not where I would of put the hole ( the lower part of the drivers side rear quarter panel) For me it would work better in the upper part. I think it would get better SWRs. That being said without seeing your pic I can't help much sorry.
Oh I almost forgot. You have a neat web site and some cool personal pic of home life and wheeling. Your K5 looks good in the pic a realy good find for 500$ But after seeing what the rust did to your's my 83 will stay in Colorado.
Eric