[Q] Chinese WINCE 6 Radio - Can you add wifi or 3G/4G dongle?

I recently purchased & installed a double-din Chinese-made radio in my car. It is WINCE 6.0 based.
(As a new member I can't yet post links, but the unit can be found on ebay by searching for "8" Car SUV Stereo GPS NAV DVD Player Radio BT HONDA CR-V 2007-2011"
It wasn't my original intention for this unit, but since I learned that it is web-enabled I thought I might investigate what is required to make that work. The unit is supposed to be able to access the internet with a 3G SIM card, although for the life of me I don't see a SIM card slot anywhere on the unit- any ideas where this is?
Alternatively I wonder if there is a way to connect a 3G or 4G USB dongle to the unit, a wifi dongle, or perhaps use bluetooth DUN to connect to the internet through an app such as PDAnet.
I have been searching the web specifically for this info and the closest I have come is through this forum, but not specifically what I'm looking for.

Thanks,
Jesse in Atlanta