what options do I have?

[obiparis]

Hi,
I have a 02 X5 4.4i with NO NAV, NO DSP, NO CD CHANGER. Production date is 08/2002. I have a Ipod Nano. It seems like I need to upgrade the radio unit to 03+ if I want to use Aux input. After some research here, it seems like Icelink is the way to go.

We also have a 99 540i with DSP. I also want to play IPOD on this car sometimes. I like to flexibility of using the FM transmitter so that I can use the Ipod on any car. but sound quality sucks.

Here are my questions:

1. I don't like the sound quality on the X5 and may eventually upgrade. Should I still go for Icelink now or wait after the upgrade?

2. If I want to use the Ipod on both cars without the FM module, I'll need two Icelinks? Do I have any other options in terms of flexibility?

3. I drove the new 530xi last week. I like its sound quality. I'm not an audiophile. What do you guys suggest for the audio upgrade on my X5?

Thanks in advance.