(Windows? No, haven`t done an X5 as yet) Jaguar / Merc
As far as your comments on the OEM security
How fast could you get in the car, wrench the lock on the steering wheel and plug a device into the diagnostic socket?
Less than a minute? Less that 30 secs with the adrenalin pumping?
Thats what the pro`s are doing !! Yes, a lot of Vauxhalls can now be started and driven by plugging a device into various ports around the vehicle. Some of the methods for stealing cars are so sophisticated that many of the aftermarket alarm companies now employ criminals to advise them. On a training course I went on a few years ago, there was a demonstartion using a car from the audience as to how fast it could be removed. There was a team of "ahem" experts, and they put a screen around the car to prevent us from seeing what was done.
The Merc 350 was opened and driven off in 15 seconds with no visable or physical damage done (steering lock on - but they said it would only take another 10 seconds to break that)
That was a fairly modern car - How old is the Omega now?
Want to rethink the aftermarket security