I got these numbers by downloading the UK Mirage owner's manual (page 11-5) -
Maximum towable weight With brake 200 kg (441 pounds)
Without brake 100 kg (220 pounds)
Maximum trailer-nose weight 25 kg (55 pounds)
Maximum roof load 50 kg (110 pounds)
Seating capacity 5 persons
I added the # of pounds in parentheses.
The Mirage is not much of a tow vehicle, & Mitsubishi isn't sticking their neck out to far on that one. A hitch might be handy for a rear bike rack, but it's not rated for much in the towing area. My steel trailer empty weighs way more than the limits indicated.
The UK website has a nice reference to towing with a Mitsubishi, but the Mirage is not included in the discussion.
I hope this helps?