Its the RNS310 on the Polo. Its not as good as the RNS510, as it doesnt have a hard drive, and has a smaller low res screen. I think VW think the price premium for an RNS510 on the Polo is too much so they are offering the cheaper RNS310 instead.
Thats why with my order for the new Polo GTI i have bought a 2nd hand RNS510 from the 'bay instead which will be fitted as soon as the Polo is delivered.
Edit. Steve, never heard of that one above. Thought the OP was talking about the RNS310 too.