03 Hybrid clunk

My dad was testdriving a 03 hybrid hes considering investing in. My dad owns a body shop and the car needs alot of body work. We could get it for about 4500. it needs 1000 dollars worth of work. only problem is there is a wierd clunk when the motor starts up after a stop and the car starts rolling. Like something is slipping then catches. We dont know much about these trannys or how they work. Anyone else ever experience this?PS contacted dealer, they had no idea what the problem was.