i traded in my mustang for my camry and left my speakers in it.

at first i wasn't pleased w/ the quality of the sound, but my hubby did some tweaking w/ the settings and it's decent for now.
i bet it will be a couple more months before places start to sell aftermarket head units & speakers for the 07. crutchfield has some, but everything is a modified fit and speakers aren't available on their website yet. here's what they say installation of a CD player:
Modified Fit - Requires Modification
Installation Details for your 2007 Camry
» Caution! You will need to modify your vehicle to install this product. We strongly recommend contacting a Crutchfield Sales Advisor to discuss your installation and your options. Modifications may include cutting wires, plastic, or metal, and may include fabricating brackets, panels, or other parts, and the installation instructions or guides we may be including do not cover these modifications. Once your vehicle has been modified, it may not be possible to return it to the factory specs or appearance.
» You will need to fabricate a mounting kit in order to install your new receiver.
» If the factory radio is replaced, the factory AUX input connection will be lost.
» If your vehicle is equipped with a factory hands-free cell phone interface, it will be lost if the radio is replaced.
» You'll get free lifetime tech support for as long as you own your gear!