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Puzzled by a strange box on dash

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New Member
Hi everyone!

I bought a pre-owned car recently, a Mazda Cx-7, and it has this strange box sitting on the window, near the mirror. It has a wire running into the headliner, but no identification on the box itself. I can't make any sense of what it could be... the dealer I bought if from also had no idea. Would anyone here know?


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Les Jones

Well-Known Member
Most Helpful Member
My guess would be that it is an amplified antenna. Probably for FM or DAB radio frequencies.


dr pepper

Well-Known Member
Most Helpful Member
I had one similar on a car a while back, only the 'rods' were tapes stuck to the glass.
It didnt work very well.


Active Member
This is just an concern of what could be, reading this may have some info on what that could be, HOWEVER, mainly assumptive and just mentioned as an aspect of what ifs.

The main box (controller) that goes to this antenna array could be located not so far away, say the passenger dash area visible from underneath the glove box or the drivers side area, or at the radio itself an odd placed box could be seen. Minor concerns as to what it "may" be revolves to just asking you to check with your local laws for your state overall containing info on jammer/scanners use even if that box does not do so, an Google check should provide up to date info via the city/state law library for info on radar jammer/scanners use. My reasons of speculation are that some areas such as Virginia in the US is illegal for radar systems of all kinds at some point or another, main reasoning is some individuals offer an illicit service to modify those types of boxes to change their internals to perform such task whilst being in disguise enclosures.
That may not be the case here

An example that I'm aware of. (this is purely assumptive and no cause for outright alarm)

I just imagine you getting any form of question about that box from any officer for whatever the reason and not having quite the correct answers for it, a potential long effort could start resulting in you having to get info from the dealer as you bought the car with that object and provide adequate proof of this and the resulting of whom installed it and as for you getting the end of what that person has done, ect, ect. for them (the prev owner not being able to remove it if it is an modified box) what if the car was reposessed and the owner was unable to remove it, afterwards not wanting to draw attention to it regardless, cuts losses and forgets it. There are radar jammer detectors used by patrol cars, tho many racers here :EDIT that use jammers during their street races (as an example): turn them on only when racing in the city, other times they are off and can cause speculation as to what they "could" be when noticed as they have to be located near the roof to work as a jammer period.

Only other thing is a radio amp, tune in a weak station with static and some music trying to sound through, then use an metal object such as a coat hanger or equiv, then place it close to that antenna box, listen for sound changes from the stations reception, try a few stations to determine if it is in fact for the radio. Also could be for cellphone amplification. Again the usual case is noted when it's not know as is practically all ways the case from any one looking at it, speculates, it's a jammer or an alarm system add on for a pager and so on....

Sorry if this causes any kind of concern towards something being done wrong by some one else the potential. Just here in N.C. they impound the car until whatever can be sorted out when a jammer is suspected.
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At first glance, I thought it was a highway toll transponder (e.g. EZ-Pass). However, with those side bars I think you guys are correct.
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