It seems crazy that you cant upgrade from carrara 4 especially as Carrara 5 is free on a mag. I dont know if they would allow you to register Carrara 5 Standard without the magazine. (It is a link on the Daz webpages you need to go to. It generates a registration numer for C5 standard. Probably not leagl though.) 

 

If you get no joy give me a shout as I have a copy of Carrara 5 standard (bought and never upgraded to 6) and also a free copy I got through the registration through that magazine.

email to contact me is mykyljjr 'at' googlemail 'dot' com.

Cheers

Mike R