In this budget you can go for Maruti Celerio, Hyundai i10 or Honda Brio, all three cars are quite good. If we compare these cars with Beat, all three cars are better than the Beat. Out of these three, Maruti Celerio is the latest and comes with best mileage of 23kmpl, also Maruti Suzuki's after sales service and resale value is also a plus point here.
Datsun Go comes with a mobile docking device with front speakers, so you can play music saved in your mobile through this system. There is a USB port, but it is to charge electronic devices and doesn't support USB devices.