Personally speaking, they sure do, because both the cars carry a similar looking mono-space design. Those who do not keep much knowledge about cars can definitely mistake an Estilo for a Nano, and I say this because I have actually seen some instances in real. Jayadev has posted a nice quick comparison image here.
ofcourse they dont look completely alike but yeah they have slight similarities. i second that nano looks much cuter than ugly estilo. no offence to owners.