If you can find the SAE plug in a 90, adding the mc4 ends on it is trivial.
I originally wired my panels to my OEM SAE connector by building my own plug, mine was installed in the fridge vent so it came out horizontally so I didn't need the 90.
I don't believe the SAE plug is strictly waterproof either so I'd consider adding some tape at least or something around the connection to make it more weatherproof.
Below is a link to another install where the OP hollowed out the plug and used it to run the wire inside without adding any new holes which I thought was pretty clever.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27976350.cfm