No amount of searching on 356 variants/ assorted keywords etc. found this monster. Must have wasted 5 hours on it. Most frustrating. If only I had added "Argentine" to my search.... it would have been in the top row of returns!
I had absolutely no idea about the car - but I recognised the hub caps. It wasn't until a couple days later that I remembered the term "concept car" - and then it was an easy find!
I guessed it would be Italian, so I started going through makes from a wikipedia list. Fortunately the make started with "A" or I could have been at it for hours!
I found the answer on an old forum elsewhere that was discussing good looking four-door cars. It seemed like a fitting place to look, and sure enough, after several pages, there it was.