most basic alarms are shoved up the steering column. a good installed would figure out where the best place to put the brain woul dbe and wouldnt do a CC halfass job.
the twoway is only as good as the installation.
i'm goign to install the minipiezo in my car with a battery backup and set it up with tweed switches so when it comes on it stays on until you shut it off witht he dedicated switch.