Hi bud,
Great news, you can finally "play around" now with the car. There is some decent power that can be released on that vehicle, and achieved with great reliability.
Those motors are one of the best diesel in the market. As above is correctly stated, you can do the following in terms of power gains but also practicality:
1. Downpipe (removal of the CAT to allow the turbo to spool more freely).
2. Engine software (to get those horses unleashed)
3. BMC or K&N Flatpanel filter (the car beathes a bit better and also, lifetime washable which also helps with further costs of servicing as well)
4. Gearbox software (does improve the drive and experience, many many features and gains however you need to check the packages and if you will want it, a lot of guys do it when pushing power or they feel their gearboxes are just not doing things up to their standards).
5. Intercooler - An option that comes with all the MPPK packs from BMW, however again depending on what you after, this can be done or not. Ideally, the 320ds dont require this with the above mods and easy reliable power.
6. Reliability wise - You must check your boost seals for any leaks or sweating of oil because once you have software and push more power, these can be easy weak points. Seals are cheap, easy to fit. your car is still low mileage so you should have any other things to look out for.
All the above can be done by Xcede, one stop shop and for decent pricing. They are under the vendor section as well....or chat to
@Sherwin@Xcede or @Singh911.