Rav4 Kickdown clonk

[Targarama]

Just been for a test drive in a 1995 Rav 4 2.0 Auto, 'new' car for my Mum. There is a clonk from the drivetrain when I kick it down as hard as I can. Any guesses whether this is a normal feature? It doesn't feel like its coming from the front or gearbox area in particular, nothing rattles or clonks otherwise (except if you move from P/R/N/D and back too quickly with the gearlever while stationary).