Exclusive, Sport Pack, Individual, Base are basically "kits" that BMWs come in.
These are generally cosmetic add ons i.e. bumpers, rims, and interior trim options, though some come a few extras like sport suspension.
Each of these options come with different rim and tyre setups (16", 17", 18") interior setups (wood grain, carbon fibre, leather seats, sport seats, electric seats, centre arm rest, sun roof, etc).
you can add to a spec though. e.g if an exclusive pack comes with 16" wheels, you can ask for the 17" wheels if you like at an additional cost.
it usually depends on the spec youre looking for. If you like a sportier look and feel, go for the sportpack or individual (once again, there is a difference between the two options), or it you like an executive look and feel go for the exclusive.
the drivetrain, power and suspension are usually not affected by these setups, though there are certain "Packs" that have a modified suspension (factory lowered, tightened dampers).
its up to you. you also go with the basic ("start" in e90 terms that come with the standard wheels, and the usual basics - leather, aircon, power steering, abs, dsc).
If youre buying a car under factory warranty, they pay for all mechanical and electrical components (usually with no cost limits). if youre buying a car with an aftermarket warranty, they pay for certain mechanical and electrical components (usually WITH cost limits, based on age and mileage of vehicle).
hope this helps.
