[Silver300CRD]

Hi
I have the same model as you and got it around th end of Feb. I have searched fruitlessly for a solution to the problem of upgrading the REG unit. My paticular aim was to achieve an AUX in and video for the kids. I wanted to move the A/V media box I had in my old car to the 300C and have music through the stereo and video front and back.
There is a way to achieve an fully wired AUX and that is to have the rear VES ( DVD) fitted at about £2500 or E4000. I did n't have the cash. In the end I have fitted a hardwired rf modulator. That is, a type of FM transmitter, but it is very low powered anddoesn't actually transmit accross free space. You interupt the regular ariel input and slot the thing in between the aerial and the radio. Its what Chysler can sell you for about £178 fitted but was £19.00 at Maplins. I didn't want a dash mounted switch so made a small infra red control which sits in the glove tray. Cos I was feeling creative I made it switchable between two inputs, one is wired to the Garmin by the drivers pillar and one to my new Ipod. You do have to go through a procedure of selecting a pre-selected radio channel and all together it is not as convenient as it would be if they had just spent another tenner on a better stock radio. Dont even get me started on where to mount the Ipod. I have ended up making one from aluminium stock. It took all weekend to polish up so it looks like the facia. I will try and up load some photos later in the week.
If you want an easy life, have £180.00 and already have an Ipod....go with the dealer ipod option it will reduce long -term-hair -pulling -out.
My installation works fine and looks quite neat but not for the faint hearted.