That's not bad at all. It will go even faster if you ever do anything else to it. I recently re-did mine and it took about six hours total. Added new head unit, moved amp to back wall, added amp for subs, re-ran new speaker wire, re-routed speaker wire (I took shortcuts the first time), ran new RCA cables, new remote turn-on, new power cables, new grounds, etc, etc...

It's quite a job. My lower back was killing me yesterday--be glad you spread yours out over two weeks.