Hello Iendicott,
I came across a number of "hacks" to ssh into the Mazda 6 - just Google "Mazda 6 SSH", you have a few options. It seems all what you need is an Ethernet to USB adapter to connect your laptop to the car. It brings interesting options, such as fixing menus, adding drivers, link to Google maps, etc... According to one of these posts the system is an ARM based linux install.
However, these are hacks. So personally I would use with caution and stay away until your warranty has expired.
Good luck