Apparently there are a lot of known problems with Bose radios in Mazdas. You didn't mention a model, but there are specifics regarding the Miata. For example: http://groups.google.com/groups?q=2004+bose+mazda+radio+problem&hl=en&lr=&ie=UTF-8&c2coff=1&safe=off&scoring=d&selm=a80021b38c44f4d9e9d0b7e6eebe3074%40localhost.talkaboutautos.com&rnum=1 "My 2004 Miata, Bose radio has a sound delay from 5 min to 1 hr before it will produce sound. Mazda replaced radio twice and amplifier once, but still same problem. Anyone having same problem, or know who to fix problem?" Some older models have problems: http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&c2coff=1&safe=off&frame=right&th=d6128ea808d60673&seekm=et7fiukdegl48nqnnejohg4cmrpa1rmh2j%404ax.com#link1 "My 99 Miatia with the Bose system did exactly the same thing. I disconnected the battery for about a minute and mine has worked fine ever since. I never could figure out what caused the problem since I didn't jump start or anything." Some information about the Miata Radio switch problem: http://www.miata.net/garage/radio.html "If your stock AM/FM Miata radio does not always turn-on I've found a simple no-cost fix that almost anyone can do. This common problem is widely reported on the Internet and other places. As Miatas age the problem often occurs in high humidity conditions and may occur when the car has not been used for several days. " Other information in discussion groups: http://groups.google.com/groups?q=bose+mazda+amplifier+problem&hl=en&lr=&ie=UTF-8&c2coff=1&safe=off&selm=a80021b38c44f4d9e9d0b7e6eebe3074%40localhost.talkaboutautos.com&rnum=1 http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&c2coff=1&safe=off&frame=right&th=356f3d569c13b683&seekm=aod0cg%24kvmsu%241%40ID-100203.news.dfncis.de#link1 http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&c2coff=1&safe=off&frame=right&th=5fb8fe0ae05b4961&seekm=5WX93.2207%24xJ.39857%40newse3.tampabay.rr.com#link1 Here is a place that mentions fixing Mazda Bose amplifiers: http://www.carstereohelp.com/mazda.htm "Speakers snap, crackle, pop, sizzle, have high pitch squeal, sound distorted, low or no output. Defective BOSE amplifier, $90 each." Other problems: http://www.miata.net/garage/nbaudio/ "My Bose stereo sounds terrible! A) Most people think the Bose system sounds pretty bad, and after 3 months with my car I tend to agree. With the bass and treble controls set at the default positions, the radio has boomy, poorly-defined bass and too much treble, but no midrange. I set the treble control down two "blocks" and the bass almost all the way down to get halfway decent sound. But it's still boomy sometimes! Also, there is a known problem with the early ('99) Bose door speakers. They tend to get wet, and when they do, they start to buzz like blown Wal Mart specials. Your dealer will probably install a set of baffles to keep them dry if you complain, or you could order some baffles from a place like Crutchfield or a local car audio shop and put them in yourself. This will help, but some folks like to install some dynamat-like sound dampener in the door panels in addition to help keep the buzzing down further." Hope this helps. Burney