not really. it may share some aesthetic similarities but it is 100% australian engineered. the wiki page is incorrect, they have it's 0-100KM/h time down to 2.98 seconds. if i remember correctly the 3.7 second time was with a cast iron prototype engine!
also the Mclaren is a V12 whereas the Joss is a V8, quite a difference in the engine. the Joss also has slightly faster acceleration 0-100KM/h.
edit: by my definition an Australian "version" would be the same car rebadged or modified in a small way. e.g. like in america the new Pontiac GTO is pretty much an Australian Holden Monaro.
lingenfelter corvette... 427tt 800+hp , 1/4 on slicks 8.9 seconds one of the fastest street legal cars in the world.. and only around 100k who needs an exotic?