[MilCom] "Stealth" Antennas for Mobile Monitoring Milcom/MilAirr?

[Ken]

While mobile presently I use the stock whips with my portable that hang from 
two clips/elastic band on the air vents with the antennas protruding just 
above the dash board.  The mobile scanner sits on my insulated lunch bag in 
the passenger's seat facing me & attached is a telescoping antenna that lays 
on the dash board (almost clearing the top)...  With this setup, it appears 
that I get a fair copy of military aero (at least ID'd) for approximately 75 
to 100 miles,of course with some electrical inteference (e.g. heat/ac fan, 
windshield wipers).  I also carry a magna mount, all band scanner antenna 
stored in the vehicle that I sometimes use when parked "on scene".

Anyways I'm looking for ideas on "stealth" monitoring antenna for 
milcom/milair monitoring.

I'm wondering if anyone has tried one of those AM/FM antenna couplers that 
allow the scanner to be used with the installed whip antenna on the vehicle? 
I'm really not interested in installing another antenna outside the vehicle. 
I know one milcom hobbyists who actually uses a cellular magamount antenna 
and finds that this works very well, so perhaps a specifically tuned antenna 
for aero really isn't necessary.    Also I've seen advertisements for 
coaxial type antennas that basically get wrapped around the inside of the 
vehicle....  Again my key interest would be how the antenna performs in the 
typical aero bands as well as air/air VHF highband tactical freqs.

Ken