2003 BMW Z4
After the first test drive, I already had a few modifications in mind, but Lisa wanted to keep it stock for a while. That lasted exactly four days after we picked up the Z4. On Wednesday night, H&R Sport springs were installed which dropped the ride height 1.75" at all four corners. Thanks to UPS misrouting one of the rear wheels to Springfield, the wheels didn't go on until Friday night. Ahhh, much better! Hawk HPS brake pads replaced the dust-o-rama stock pads, reducing fade and cutting down on the dust on the GT3s' polished lips. An Apexcone 4500K HID set in the foglights keeps them from looking yellow in comparison to the stock bi-xenon headlights, especially after swapping the factory 4100K D2S bulbs for new Apexcone 4500K D2S bulbs. Until UUC or Stromung starts producing a Z4 exhaust, BMW chrome tip covers dress up the boring stock tips a bit.
A couple months later, I installed a UUC Evo3 shift lever kit (~25% shorter throw than stock), a stainless steel UUC RK5 knob and a UUC clutch stop. Driving feels much sportier with quicker shifts and the shorter clutch pedal throw, the weight of the knob keeps the shifts smooth. In addition, I picked up a new BMW clutch delay valve from BMW and knocked out the internal valve plate and spring with a small punch. Its installtion got rid of the jerky first to second shifts that are common with CDV equiped BWMs.
More recently I've replaced the factory shocks with Koni Sport shocks, they're a much better match for the H&R Sport springs. A BMW strut brace went in to place when installing the Koni struts, it's non-hinged design helps stiffen up the front suspension.
After the first year of driving with the annoying traction control system kicking in everytime the road started getting fun, I yanked the factory 3.07 open differential. In its place went a Jim Blanton built 3.46 LSD. Acceleration is much improved due to both the more agressive gear ratio and the fact that both rear tires can now put power to the ground. I'd HIGHLY recommend the diff upgrade!