I have a 2012 SRX that we tow 4 wheels down behind a 2005 Airstream 30 ft gas. Have probably towed the SRX about 4ooo miles without a problem. I use Blue Ox towbars with a US Gear permanent setup for the braking in the toad. I installed the Blue Ox front tow plate, the US Gear braking device/wiring, and the rear permant wiring for the stop, tail, turn signals in the SRX myself. Not too hard to do and you save big $$ at the expense of your time but when you are retired, it's almost fun.
Before you tow, according to the owners manual you need to pry up the edge of the boot around the shifter ( I use a small flat screwdriver) so that you can stick same screwdriver in the hole nearest the motor and then shift from park to neutral. Engine,lights radio etc must be "off". It helps to learn where the neutral position is by first trying this with the engine "on". You can then lift the boot to see where the neutral position of the shifter is. (With the engine on your shifter position will light up on the dash.)
As far as I know pressing the button in the hole lets you shift from park to neutral without starting your engine and putting your foot on the brake pedal. This frees up the steering wheel so that the front wheels will turn to follow your M/H. I believe that it also negates the need to pull a fuse as you need to do for some other vehicles. And no the odometer does not move when under tow.
Also your owners manual will tell you to run the engine for 10 minutes before you start your days towing, when you stop for lunch or fuel and when you are finished towing for the day. This lubricates your tranny and cools it off.
Also your manual indicates that your top speed should be no more than 65 MPH when towing to avoid overheating the tranny. I tow around 60 mph.
Hope that this info helps.