I have CLK-320 year 2000, the radio is restarting while I am driving.

The radio is brand new Pioneer, it operated well for 3 month.

If I stop the car and shift gear to neutral N, the radio operates and does not restart.

While I am driving the radio restarts every min or so, especailly when speeding or decreasing speed.

Any idea, or advice for what should I check, will be very much apperciated.

Thank you in advance
Regards