Upgrades for 2008 128i

What is the biggest size rim can I put on my 2008 128i?
I would like to upgrade my sound system, I know what speakers I want but what Player do I go with I want it to have an iPhone adapter since I can not play music through Bluetooth with my car

I've heard 20" rims, that's what a salesman at Tirerack told me. Can't help with the audio question.

What are you going to do with the wheels that are on the car now? If 4 sale let me know.

19 is as large a diameter as I would go (but prefer 18s personally). This would achieve an aesthetic look while not negatively impacting the drivability and overall wear and tear of the suspension, steering components, etc.

Anything larger, and I can almost guarantee major repair bills, alignment problems, and degradation in handling performance in the relatively near future. Not to mention the rattles and squeaks the car will develop from the beating it takes----every inch in diameter makes a HUGE difference in the roughness of the ride of this car, not limited to, but especially if it has the sport suspension.

Originally Posted by Joe.garcia2616

What is the biggest size rim can I put on my 2008 128i?
I would like to upgrade my sound system, I know what speakers I want but what Player do I go with I want it to have an iPhone adapter since I can not play music through Bluetooth with my car

IMO, an upgrade in sound or performance is worth it to the owner, but where is the upgrade in a larger rim? Again IMO this has absolutely no value, unless someone is willing to pay more to buy your car. From what I've heard, most cosmetic "upgrades" have no real value.