The eibach pro kit is an excellent choice for most frequently driven street cars and provides a very good balance between looks and performance.
It lowers your car enough to clean up a lot of the wheel gap while still keeping the vehicle's ride quality at or near stock, which is very important to many customers.
It uses progressive rate springs that allow the car to start with a soft set of springs that are firm but not jarring when you drive hard and then get stiffer as your vehicle corners.
This combination of springs and wheels & tires helped to complete the sporty character of the GS300 as it ran the fastest lap times in a test we did on the track. The ride is very good despite being on 20" Michelin Pilot Sports, the progressive rate springs soak up the small road irregularities while making a gradual linear transition as you drive more aggressively into higher speed corners.
Combined with Eibach's anti roll bars the springs, wheels and tires provided balanced handling perfection. The GS300 was very eager to turn in with less body roll, was much more stable in corners and regained composure quickly when driving off the track.