Assuming that the total is within the specifications of the charge controller, the key is to use the same PV technology and not introduce partial shading. Both panels should have full sun exposure, since if one is often shaded (like being too close to something tall, like a stowage pod), then it will just slurp the power from the other.
There are work-arounds for this, involving more electronics... from the trivial (and inefficient) insertion of series Schottky diodes to the efficient (and expensive) addition of another whole controller. But if you have them all as one full plane, that's easiest, and works just fine if the controller doesn't mind the larger array size.
Another thing... if you parallel panels, the current in the wires doubles. Since power loss in cable is a function of the square of the current times the resistance, it is a lot more efficient to put them in series... higher voltage, lower current. This is particularly important to consider when adapting a factory installation with the original cable, since it was very likely sized according to the installed array. However, I don't know if the controller can handle the higher voltage... most do, but check the documentation first, and make sure it's configured accordingly before hooking it up. If you do them in series, the net efficiency of the system will be greater.
Cheers,
Steve-who-does-not-have-a-Ranger-yet
