I've had a few of these interactions, and absolutely love them.
I had one the other day where I'd stopped at traffic lights in my local area (never having seen another Gren in my area), look across the intersection, and there's another Gren on the cross street! What the? So I did the best thing to grab their attention, and tooted the Toot horn. Instant recognition, and a wave, and off they went!
I was off to the Gold Coast a few weeks back to get some stuff done on the Gren, and stopped in a servo for fuel. As I came back to the truck I noticed a guy and gal having a look at it, and wondering what it was. About 10 mins after having a chat, they were in the process of disposing of their existing car and house, and planning on buying a tow rig and caravan to do the lap around Australia. The Gren now features right up on their list of vehicles to consider, after I told him why none of the others really matter in the 3.5T towing class.
My best one was about a month ago, when I was trying to find a phone holder for my mobile phone (after the existing one kept unsticking from the front window). I went into a BCF store (camping and fishing store here in Aus), came out with a few purchases, and noticed the last of the original Defender 110's next to my Gren. I had one more store in the area to check out, and hoped that the vehicle would still be there when I returned. About 10 mins later, as I came back to my truck, it was still there. As I hopped in the Gren, I thought I'd just wait a minute or two to see if the owner would return, and yup, an old bushie appeared from a shop, and began walking in my direction. He told me that he parked next to the Gren as he was curious about my car, and thus was hoping he'd see me too!
We spent about 30 minutes chatting and looking at each others vehicles. Great fun having a chat with a complete stranger, who was as passionate about his Defender 110, as I was of my Gren!
