Carplay & Android Auto Head Unit for R230

I can give you two suggestions,

Smarty Trend head units

• You can customize which specifactions of device you want
• It supports both android auto and apple carplay as wireless.
• Check for details and price https://smarty-trend.com/en/mercedes-benz-sl-class-r230-2001-2011-android-head-unit-carplay

Sigma Car Stereo

• It’s plug and play so easy to install.
• Supports wired android auto and apple carplay but you can also upgrade to wireless.
• Check for details and price https://www.sigmacarstereo.com/android-head-unit-upgrade-for-mercedes-benz/mercedes-benz-sl-class-r230-2005-2006-2007-2008-2009-2010-2011-2012-radio-upgrade