There are two factors in play here and your scenario only accurately measure one:
1) If GM cars security is the best of the market will it carry any weight in the purchase decision (as compared to all the other factors)?
2) If GM cars security is not the best of the market and one of their security incidents make headlines in mainstream TV and newspapers will it carry any weight in the purchase decision (as compared to all the other factors)?
People don't pay attention when things that are supposed to work properly do so but when they don't it carries a lot of weight in the purchase decision. See the Toyota slump [1] in the U.S. market share between 2009 and 2011 caused by many factors but certainly with a contribution of the bad news related to the recalls [2]
1) If GM cars security is the best of the market will it carry any weight in the purchase decision (as compared to all the other factors)?
2) If GM cars security is not the best of the market and one of their security incidents make headlines in mainstream TV and newspapers will it carry any weight in the purchase decision (as compared to all the other factors)?
People don't pay attention when things that are supposed to work properly do so but when they don't it carries a lot of weight in the purchase decision. See the Toyota slump [1] in the U.S. market share between 2009 and 2011 caused by many factors but certainly with a contribution of the bad news related to the recalls [2]
[1] http://online.wsj.com/mdc/public/page/2_3022-autosales.html#...
[2] https://en.wikipedia.org/wiki/2009%E2%80%9311_Toyota_vehicle...