installing amp and subs

i'm gonna be putting in an amp and subs in my GT. I have the 8 speaker bose system and am very pleased with that, i think it sounds awesome. anyways, i was just wondering if this would be a good wau about installing another amp and sub. i figure use a line out converter on the rear speakers for RCA's, just run the power from the battery to the amp(obviously) and then just use the stock amp in the trunk to tap into for the remote wire. i like the stock look. so i dont want to replace the delco deck. any info would be great.. thanks guys!

As long as your amp has an internal crossover, and you're not looking for competition clear sound, your method will work great.