Ok,
I made an executive decision not to lower my car just yet and decided to go the conservative route for suspension mods. So, from MorrisTown MINI, I have a JCW shock tower brace, and the rear sway bar from the JCW suspension kit. The shock tower brace will certainly improve steering feel and hold things together (from previous experiences, they are always worth something) and the sway bar should tighten the back end just enough, I hope! My complaint with the MINI is that on twisty, bumpy roads, the back end wiggles a bit. My old Z3 Roadster did this, and a rear sway bar (well, I did front and rear in that car) really did make a difference and helped reduce body roll as well! The parts were reasonable and who knows, I might even be able to install them myself. More when things get installed.

 

Using a bigger rear sway bar will make the rear looser, not tighter (note that on your Z3 you had replaced the front bar as well). It is the stiffest end that looses traction first (sort of counter intuitive). You will actually worsen your problem that way.

If you want to keep the back end tighter to suit your driving style, the easiest (and cheapest) thing to do would be to dial in a little more negative rear camber - that will give more grip in the corners. The rear camber is easily adjusted on the R56 (from 0 to -2 degrees IIRC). My MINI from factory was set at -2 degrees in the back and I had the opposite problem you have - it understeered like a pig.

Also check your tire pressures - rear should be equal to the front (around 36 psi), or even a bit lower if you're trying to get rid of oversteer. Less pressure = more traction (up to a point). Don't go bellow what the manual says or the tires will handle like crap.

 

Very cool! Let me know when you are thinking of installing them. I know of a garage you could use (mine).

 

I wasn't aware that the JCW suspension kit came with different sway bars. Is that normal? Or different depending on what country you're in?

OP: way to keep it OEM

 

The JCW suspension kit does come with different sway bars, in all countries as far as I can tell.

As for my MINI, I probably wasn't clear, it has alot of understeer, so the rear sway bar should help reduce this. Getting the MINI to oversteer on the street is pretty tough right now unless you paly with tire pressures alot.

Mach V Motorsports is installing the rear sway bar tomorrow. I installed the shock tower brace myself in about ten minutes. It fits perfectly and looks quite stylish. Need pics...

 

Update on the bits...
Today I did the DCMetroMINIs St. Patty's Day run. Wow, plenty of difference with just these two little mods. The shock tower brace, which of course dresses up the engine compartment a bit... does help with steering feel, especially when corning on a bumpy DC road. And the rear sway bar... tightened up the back end nicely, no more wobble in the twisties. Push the car hard enough, and you can get a little oversteer, which is fine, but cornering is definitely much nicer. I can't imagine what a full suspension kit would do, but I decided to spend that money on lighter wheels. For now, I am very pleased!