BMW: Rear Bushings and Change Spark Plugs, control arm bushing, unpleasant job

Question
Josh,
In talking to a different service shop they said they can get a control arm bushing kit for both rear sides and install those instead of also control arms + bushings.  They want $350 each side... do you think that if I get the control arm bushing kit at an online parts site that any service shop could do the install on the rear?

How difficult is it to change spark plugs?  Again I can get plugs for like $8 online vs. $15 at the service shop (that buys from the BWM dealer) and is there special tools to install plugs (and some wiring boot or something they said) or again can I or any service shop install plugs?  It's a 740iL 2001.   

Thanks!
Tom

Answer
Tom
 Yes, you can buy the bushings and have the shop install them.  Most shops make money off labor rates, AND parts.  So it's probable that the shop is buying them from the dealership or other wholesale company, and marking them up considerably.  So if you buy the bushing's yourself (from an online source, not the dealer) you will save considerably on the parts.  Just because the parts are not purchased from the dealership, doesn't ALWAYS mean that they are of less quality (where do you think the dealerships get their parts from?)  So If you check with www.bavauto.com or www.pelicanparts.com you can find the CORRECT parts at a discount.  Dealerships are notorious for making a 200%-400% markup on the same parts you can buy elsewhere.  I know because I sell wholesale autoparts to dealerships for a living.
 My my advice is to do what you said, buy the parts, and have them install the bushings for you.  I dont know if I mentioned this before, but it IS an unpleasant job.  The bushings are installed incredibly tight, and usually require special tools to remove them.  The shop could be factoring this into the price.
 
 Spark plugs are EASY, to install and remove.  They are literally a "plug" that is tightened into a hole. electricty passes through this plug and arc's, igniting the fuel.  On older cars you simply removed the spark plug wire put a socket on the plug and removed it. Install is reverse of removal, except you need to "set the gap" on the plugs.  This is the space that electricty has to "jump" across on the end of the plug.  Secondly, on the newer BMW's they have aesthetic coverings on the engine that hide all of this.  Then you have a new ignition system, where you have a coil on each spark plug.  You need to remove these plastic covers, then remove the coils and you should be able to see the plugs.  remove the plugs and then replace them.   
 I just went through the basic procedure for changing plugs, but if you are not familiar with basic tools and have limited experience, it's best to AT LEAST have knowledgable person to guide you.  You CAN mess up... and in a BIG way.  If you over tighten the plugs (unlikely) you can strip the threads out of the cylinder head, which will require tapping the hole and inserting a helicoil (headache).  So as it stands now, I would recommend that you either watch someone change the plugs or ask for help doing so (by someone who KNOW's what they are doing).
 I've rambled enough..
 Josh