The speakers may be the least of your problems. Went the same way two and a half years ago with great regret. Will be rectifying in December. In my opinion the 2008 is nothing like so well thought out as the 3008.
The 2008 is a larger version of the 208; not a smaller version of the 3008.
There's bound to be differences in space and equipment if you try to compare it with a 3008 as they're two totally different models.
Enjoy it as a 2008 and accept that it is smaller than your previous car but still an excellent car for comfort, performance and much easier to park.