Chris,
I do not know why they told you the boot (trunk) popper is expensive; I have seen cheap ones for as little as $13 on eBay.
As for installing it, all it requires is one side of the solinoid (the popper) be grounded to the trunk lid or even one of the ground wires for the rear lights and one power wire run from the solinoid to the boot release switch. The other side of the boot release switch will be connected to +12V power. When you press the boot relese button, the switch completes the circuit, activates the solinoid and unlocks the latch on the boot.
If this is going to be used with a remote opening system, then a relay is needed to connect the output of the main control unit's auxiliry output which is activated, and sends +12V to the solinoid when you press the boot release button on your remote control.
Perhaps they told you it was expensive because they were going to charge a lot of money to install it for you!
So, to answer your question, yes, that will work on your car and will work on both the 4 door sedan (saloon) and the hatchback.
** I wrote both boot /trunk and sedan/saloon so people in different contries will understand; some people do not know what the boot is, nor do they know what a saloon is.
