Still getting to know my 2000 Boxster (ok so I won't admit that I have had it in a 4 wheel drift on more than one occasion.... what a pants filling

rush! - maybe this could be a new thread - "milliseconds from losing it all..." )
Anyway, just a few quick questions.
- When I turn the engine off, there is a considerable amount of "ticks and ping" noise from the engine as it cools. This is the first "performance" engine I have owned, so I drive it harder than I did my previous cars, but not what I would consider excessive - is this normal?
- Secondly, I don't have the option with rear speakers (storage apartment just big enough for sunglasses!) and desperately want to install them. I went to the local Porsche dealer, and they said the only option was to buy a complete rear console (about $600) that already include the speakers. I am sure there are some avid do-it-yourselfers who have drilled and cut into the existing console - I would be greatful to hear from anyone who has done this. Also, would be keen to hear from other speaker adventurers who didn't install in the console.
Boxster on !!