Blackjack has a good possible solution. The right filter in the right place should help.
I have just shipped a $2,000 stereo system to my manufacturer, for install in my West Coast cobra...I will list the goodies here to tweak those who despise one of the great joys in motoring...MUSIC!
Eclipse in dash cassette with CD controller system, with remote controller (like a VCR remote)
600 watt multi channel amp in trunk
(2) Eclipse 8 CD stacks/players in the trunk
(2) MB Quart tweeters in the doors
(2) MB Quart midrange 5 inch round speakers in the doors
(1) 8 inch sub woofer mounted in the back wall at shoulder level, between the seats
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Big improvements in stereo systems recently, make actually hearing the stereo at speed , a possibility, vs the older systems many have or may be aware of. A nice accessory for the passenger is a set of plug in stereo headphones, cuts out all other sounds, let's them (rock) (oldie) (whatever) out.