Installing a new car radio

I got fed up with the very bad error-handling of the CD player in my Mitsubishi Colt, and decided to invest in a modern car radio, capable of playing music from USB sticks. I bought a Pioneer DEH-2200UB, and proceeded to install it, which I made more complicated than I had assumed it would be.

While popping of the front panel and uninstalling the old radio was not very hard

the new radio and the old radio did have two totally different connectors. Of course. I could have gotten and adapter, probably, but I wanted to try out my new radio now, dammit. So I had a look at the pin-outs of the two radios, snipped off the wires and connected them individually.

Against all common sense, I did not make any mistakes, and the radio lit up the second I turned the key. Lit up in a good , glowing-led sense, not in the bad, smoke-producing sense.

Who would have thought that automotive electronics would prove so simple?
By the way, those micro-SD stub USB key thingies (in white in the photo below) are perfect for the USB aux port of your car radio, I bought two 4 gb ones for 12 CHF each, more than enough space for music, and they are so small I won't accidentally rip them out of the radio by brushing against them.

Now I wonder how difficult it would be to install a keyless entry-thing on my own?