I think they look pretty ugly and spoil the whole point of the flush door finish, I agree if you have one mount it out of sight.
Here in the UK, our car is also fitted with an engine imobilizer, this has to be fitted to get insurance.
This means we have to carry an additional imob/code card. There is a process we have to go through once the car is unlocked and ignition is activated prior to engine start.
I get on pretty well with mine now I know the system, but I have been caught at the traffic lights in the early weeks trying to go through the process to get my GT started :confused