I don't know about Dimi Mavropoulos, I tend associate him with Sunbeam Lotuses and Audi Quattros (he used to be a regular in British rallycross with a distinctive black Quattro), but there were certainly a few around in Greece- Nic J. Theocarakis S.A., the Greek Nissan importer usually had at least a couple out on the Acropolis, as well as the neighbouring ERC rounds- George Moschous and Stratis Hatzipanayiotou (My memory's not
that good- I'm looking this stuff up as I go!
) were amongst the drivers. Works entries for the likes of Salonen, Shekhar Mehta and Mike Kirkland also appeared under the Theocarakis banner on the Acropolis.
Attila Ferjancz could have used one at some point- IIRC, he often had Rothmans sponsorship, on Quattros and Renault 5 Turbos, and I've certainly seen pics of a Rothmans-liveried 240RS somewhere recently
There were certainly a few privateers around on other European events- I've already mentioned Simon Everett on Belgian tarmac rallies, but pretty sure there were others seen on European events (there was at least one other Belgian-based car, and I think I remember Pentti Airikkala having at least one run on a Belgian tarmac rally with a 240RS), and as you say a couple in Spain/Portugal- there was a distinctive black 'Lois Jeans'-sponsored car, driven by a guy named Santinho Mendes around 1984/5, which has been modelled by one of the 1/43 diecast manufacturers:
http://i89.servimg.com/u/f89/11/19/85/42/mes_i118.jpg
Further afield, on African events (Safari, Ivory Coast), Mehta, Kirkland, Jayant Shah, Surinder Thatti and Alain Ambrosino were amongst the regular 240RS runners. There were quite often one or two Japanese privateers out on events like the Safari, Acropolis and RAC as well.
I thnk the 240RS was also fairly popular on Middle Eastern events- IIRC, 2wd Group B cars remained eligible there for a year or two after they were banned in Europe, which gave the big Nissan a further lease of life- it was always a bit more in it's element on rough road events where 2wd and lack of horsepower was less of a disadvantage against faster cars, and reliability could pay off.
There's a fairly famous film clip of a guy named Tony Georgiou comprehensively demolishing one in a multiple roll on an event in Jordan in the mid-80's.....
http://www.youtube.com/watch?v=hjUSH5-JJYw