I tried spacers on my Boxster. 7mmx15mm and then switched to 7mm all around, until just removing them because I didn't like the handling. Both combinations changed the handling dynamics with the 7mm front x 15mm rear having the most impact (more oversteer), but at least the 7mmx7mm kept the stagger consistent with OEM specs. Both setups reduced responsiveness. Just wasn't comfortable with them. And unless you're then going to get the car re-aligned and dialed in (toe/camber) to accommodate for the spacers, you're going to wear out tires unevenly and put more stress on suspension components. If you want a wider track and more rubber in the wheel well, then you need wider rims and tires on both ends of the car. Spacers are the cheap way initially, but replacing tires becomes expensive. JMO of course.
I'll probably be listing my spacers in the market classifieds if I ever get around to it lol
interesting , you would think logically that the wider stance would increase handling, hence most track cars are lower and wider.... I am set to do another alignment after the springs settle, but from what I understand the spacers don't really effect the alignment, maybe if you are doing 25mm +
anytime you lower a car your are going to have to count on going through tires a bit quicker.... the price most of us are willing to pay.
alignment specs, sway and and anti sway bars and tire pressure also factor into under/oversteer...I've read that a wider rear will tend to understeer and a wider front will tend to oversteer....it is all about finding the right balance.
haven't had much time to test it out much so far, but did take it on canyon run last night and it felt really good.