From the Bill'* pics above.. (both of us that is..lol) we can see that the S1 appears to expose a lot more of the bigger filter.

(while it'* not overly relevant in your car, the 00+ oil pan/filter in the 96-99 is up higher than the frame and therefore protected better than the steel pan)

FYI, I posted my quote above primarily for a better comparison of the sizes. I've had no problems, however, on my more exposed filter.

The K&N is longer as well due to the nut on it...

On my L27, it might've stuck out just below the frame.

If anything connected the ground might've hit it, I probably would've lost a wheel and what not first...

I run the same HP2001 K&N that Bill has on his for about a year and a half and have never seen a scuff on it when i change it out. You'd almost have to bottom out on the frame to hit the filter.