First of all, just let me thank you all very much for having such great information on this site! It's not only been a resource for Mini information, but it's saved me a million headaches, countless trips to the mechanic/dealer and probably thousands of dollars. That being said, I've got a couple of issues with my 2005 Mini Cooper S (53K miles) that I can't seem to find the solutions to on this site, or elsewhere online, for that matter.

Let's start with the easy one! On the rear caliper, there is a spring that is attached to the parking brake cable and "releases" the piston inside when you lower the handle inside the car. Makes sense, right? Well, one rear caliper has the spring...the other doesn't. So, when I release the hand brake from inside the car, the caliper without the spring sticks. I can get under the wheel and release it manually, but it would be much nicer to just find a replacement spring to do the job...however, everyone (Mini dealer & auto part stores) say it comes with the caliper and I need to buy a whole new caliper just to get the spring. This, IMO, seems ludicrous...even a used caliper can be $70 or more...seems a bit high just for a spring. Can anyone tell me if there's a place I can look to find this odd, but very useful, part? Used or otherwise?

Next problem, and pardon if it's redundant, but this is my first time posting...and as I've previously stated...I can't find the answer here. I have a shake in the steering wheel anywhere from 48-63mph. Anything slower or faster, you can't notice it. Tires & rims are brand new, balanced and it's been aligned. Only thing noted about the alignment was that I needed a new camber bolt, which left the adjustment a hair off, but mechanic said it was still within normal limits. Rear brake pads & rotors are brand new. Car also just had a rear wheel bearing replaced, none of the others needed replacing. Right front strut was replaced 8 months ago, seemingly without further issue. Obviously, tie rods are functioning since it was just aligned.

What are some other possibilities and are there any specific diagnostic tests to do with the car that I may have overlooked that would indicate the problem? For example...if it's the control arm bushings, how would I test the car to see if that's the case?

Any help would be greatly appreciated!