If you are replacing the headunit with another model RCD then you shouldn't require any adpators.

The connects2 canbus module allows you to use your stereo wheel controls, however only works with selected brands and models.

However, I changed my to an Ecplise CD5030. I tapped into the 12v cigerate light for the ACC, and tapped into the canbus for constant.
The speakers are also in the canbus, so just used my DMM to find each speaker and wired up as required.

Stereo works a treat, havent an problems.

Have also installed an amp, and replaced the factory front speakers with Alpine Type R.
These are good bang for speakers that are happily taking 140rwms each a daily.
Rated @ 110wrms fyi.

I did look at these chinese headunits, but figured they were ****.

Thanks for your feedback.