dataguy
Been here awhile...
That trunk switch works just like the doors do. You still have to be close enough to the vehicle for it to pick up your fob.
But it is nice to be able to keep the fob in your pocket and not fumble around with it. It's also nice that it doesn't set off the alarm...other cars I've had would set off the alarm if you didn't disarm the system before you opened the trunk (including my last car, a Sonata).