🚀 go-pugleaf

I have a car alarm that pages you when the alarm goes off.  It is
supposed to be a 4 watt system that can transmit for 8 miles.
I recently tested it in a very large shopping mall parking lot.
I parked the car about 200-300 feet from the front entrance and
stood outside and had someone set it off.  It worked fine.  Then I
moved a few feet just inside the glass doors of the mall and it didn't
beep me when the alarm went off.  I called the company and they said
that the range could be reduced to be that little.
     Does this happen to all the makes of beeper car alarms or is this
a cheaply made alarm system?  Is there a way to boost the range with
some kind of booster or an addition antenna (I am using my car radio
antenna)?  Does this also happen to CB's and cellular phones or do
they have much higher power transmitters?

Thanks,
Chris