I am buying a new vehicle and I have a minor issue. The roof mounted whip aerial is too long and when I go in and out of our garage it will strike the garage door(tilt door).

Is it possible to cut these shorter without loss of reception?

alternatively, is there somewhere in Wellington anyone can suggest I could go to find a replacement shorter aerial. I would like to be able to just unscrew the current from its base and

screw in a new aerial.

I have included a representative aerial similar to the one on the vehicle I am buying.