A dual 4 ohm sub can be wired in parallel to get a 2 ohm load to the amp.
Unfortunately that amp when bridged is only stable to 4 ohms, so that is not a option.
You could wire it in series to get an 8 ohm load, but it's not going to see much power.
Do you have another amp running your interior speakers or are those being powered by the headunit?
What I would do is use that amp for the front interior speakers then get another amp for the sub that can handle a 2 ohm load. Your other option is to get a second subs just like the one you have m then you can wire them in series/parallel to get a 4 ohm load to the amp
The only problem with that is that the subs aren't going to be getting that much power.