Yes, that sounds like a true VRV. So you shouldn't need to do anything but turn off the pump to drain the panels.

However, Sungrabber suggests that the panels be removed and stored before the first frost so they may not be able to survive the winter even if the water is drained from them. But you should problaby check with the manufacture.

This is from their web site:

Q. What do I need to do to winterize my system?
A. The panel must be drained and stored before the first frost. If water is allowed to freeze in the panel, it may cause freeze damage. To winterize your system:
1. Turn off your pool pump.
2. Place the plugs given to you with your pool in the inlet and outlet of the pool.
3. Disconnect both of the hoses from the hose barbs on the solar heater. Disconnect the hose from the pool inlet. Connect the hose from the pump to the inlet on the pool.
4. Remove the plugs from the inlet and outlet of the pool and check the hose clamps you just tightened for leaks.
5. Unscrew the white drain plug that's located on the panel end opposite the inlet and outlet.
6. Roll the panel and secure using the yellow/black -carrying strap. Tilt panel until water no longer comes out. Replace drain plug, and store the panel and plumbing in the garage or a shed until next spring.
It sounds as though the water in the panels is the issue and would not be a problem if drained properly but they still suggest that they are removed. Other panels can be left up during the winter but is seems as though these cannot.