Ressull I'll tell you what I know - I suspect otherwise you will be waiting a considerable amount of time for a response (see my thread in this section...)
If you have no USB socket, your best bet is an aftermarket solution. The OEM cable / iPod interfaces have limitations (max. 250 folders I think - it sees the iPod as a "CD changer" like most interfaces of this type).
Not sure if you have multi-function steering wheel, but most of the aftermarket options allow you to use it with the iPod.
Mike @ newministuff.com is the guy to talk to, there are a range of options with widely varying prices, BUT for me (someone who is asking the same question and had to spend hours looking for answers someone on here could of helped with in a few mins) - the best one is the Dension Gateway 500.
The Dension requires you to get your vehicle recoded either by Mini or someone with appropriate hardware though (not sure on cost, currently waiting on cost from Mike).
Alternatively there is the Parrot 9200 - instead of displaying iPod interface on your Boost speedo however, it uses a dedicated colour screen which is provided (which I don't like). It DOESN'T require you get your vehicle recoded.
Both these options have Bluetooth AND iPod compatibility and work with steering wheel controls (only the Dension displays iPod info on speedo display - not sure about phone info).
Good luck (get in touch with Mike - theres a pic of the Parrot kits on newministuff.com)