You mention the back seat as a negative..

I'm 5'8.5 and manage to fit comfortably in the back with my boyf driving who's 6'3

Now he wouldn't fit quite as comfortably but anyone under the height of 5'10 i reckon would be comfortable enough the back of the polo..

I didn't buy my car with the intention of fitting people in the back so it doesn't really bother me if on the odd occasion i have to sit in the back..