Try the many on-line auto parts sources, such as; www.autopartswarehouse.com, www.rockauto.com, or www.arnottindustries.com for the replacement parts. For example, they (Arnott Industries) list the rear air bags from around $99.00 each for your vehicle.

Simple answer - the kind (brand or design) that is correct application for your vehicle. Maybe check with other BMW owners - see what they like or have experience with. Having owned a late 70s BMW - I liked the Boge brand for my car - but it depends.

Try the many on-line auto parts sources, such as; www.autopartswarehouse.com or www.rockauto.com for the replacement parts. For example, they (RockAuto) list many different struts and shocks for your vehicle.

The cost for the repair would vary depending on the repair shop, the location, and the labor rate charged. Try the 'Find-A-Shop' and 'Estimate Cost' features on the AutoMD website.
The actual parts cost can be determined at any of the on-line auto parts sources, such as - www.autopartswarehouse.com, www.rockauto.com, www.pelicanparts.com, or www.partsgeek.com - to name only a few.

I had the same problem (04 745Li). In my case it turned out to be the altenator.

Prolonged driving on overloaded/underinflated tires or a road hazard are the most likely causes, if the sidewall separation/bubble appears after six months of on-vehicle service. However it may take weeks or months after an impact for a separation/bubble to appear as the damaged or bruised area continues to weaken. I would suggest that before you buy he vehicle the suspension system should be check by your friend/trusted mechanic. Because if the past owner hit a lot of potholes like the dealer said the suspension of the vehicle should be affected.

Recommend wheel alignment first to see what's wrong w/ the suspension& steering. Could be also bent wheels from hitting those pot hole.

Depends on the engine, if its an M62, the steering reservoir is under the hood, towards the front drivers side. If it an N62, the reservoir is on the underside of the vehicle, next to the oil drain plug. Its the black plastic housing with a 6mm allen bolt in it (thats used to drain the oil out before removal).

There is honestly no accurate method to determine vehicle condition via the internet - especially for any accident damage. There is too much unseen and beneath the surface.
Only a personal and up-close inspection will enable an accurate assessment of the damages and needed repairs. Personally, accident vehicles I steer clear of when considering a used vehicle - one cannot know all the damage or the extent of the circumstances involved.

As long as the power steering fluid has been checked and the level is full, then most likely, the cause may be either a faulty power steering pump or faulty steering rack and pinion unit.
Check the many different on-line auto parts sources; such as - www.autopartswarehouse.com, www.partsgeek.com and www.rockauto.com for the replacement parts. For example, they (RockAuto) list the power steering pump from around $90.00 (minus core charge) and the steering rack assembly from around $256.00 for your vehicle.

Check the local library and the auto manual reference section. You can also try these websites; www.manualspace.com or www.diyrepairmanuals.com.
Check the many different on-line auto parts sources; such as - www.autopartswarehouse.com, www.partsgeek.com and www.rockauto.com for the replacement parts. For example, they (RockAuto) list the front left lower control arm from around $29.00 for your vehicle. Remember to always replace the control arms in pairs - due to mileage / wear / age considerations.

Check the local library and the auto manual reference section. You can also try these websites; www.manualspace.com or www.diyrepairmanuals.com.
Check the many different on-line auto parts sources; such as - www.autopartswarehouse.com, www.partsgeek.com and www.rockauto.com for the replacement parts. For example, they (RockAuto) list the front left lower cotral arm from around $29.00 for your vehicle. Remember to always replace the control arms in pairs - due to mileage / wear / age considerations.