I am looking at doing a modest upgrade of my audio system for my 2007 Cabriolet. I have the stock system with stereo controls on the steering wheel.

Based on a not as thorough as absolutely necessary review of this forum, the best "bang for the buck" would be a speaker upgrade, focusing first on the fronts and then the rears. This would also allow me to keep my steering wheel controls.

Key assumptions:
- the stock speakers are very cheap (both from the forum and my own experience)
- Most 6 and 1/2 - 6 and 3/4 speakers should fit the front. That would be the first speakers to replace. My understanding is there are quite a few "good" speakers for $50 - $100. To maximize the response quality from the underpowered stock receiver, I would go speakers that have maximum sensitivity (ie. 92dB)
- Next would be the tweeters in the front and then the rears.
- I would be doing the work myself. The major challenges would be taking off the door panels and drilling new mounting holes.
- I don't need to install a crossover

Do these assumptions make sense??