Regarding the speakers as of now my only suggestion is to give a call to the factory and ask if they can provide you specs of the item no. MMM10625
Here the speaker
http://www.aero-racing.co.uk/partsbooks/supersports/doorinternals.htm

And it's grill
http://www.aero-racing.co.uk/partsbooks/supersports/doormirrors&trim.htm

Unfortunately to dismantle the door card is not as simple as expected. If you decide to go for it, you need to start from item 11 (that is kept in place by those plastic pins and velcro and then struggle with item 18. Usually there is no needed to remove the electric windows switch. All info come from a quick chat with the dealer this Friday.
If you do it, please, take your time to document it with a few pics.

2010 Violet Aero Supersports | 2012 Green Vantage S Roadster