Does anyone know how difficult it is to add a bose system to a catera that did not come with one? I have a wrecked catera with bose, heated seats, all the bells and whistles, while I have purchased a catera that doesn't have the bose and heated seats and so one. How difficult would it be to swap in the upgraded equipment? Will I have to pull whole wiring harness or are they prewired? Anyone know?