I haven't read the whole thread, but as a rules/regulations/guideline writer off and on for a few years now, one of my personal rules is the K.I.S.S. principle...keep it simple... The simpler something is, the easier it is understood. The shorter it is, the more people will actually read it. You don't have to say everything explicitly to get your point across. Brevity is your best friend.
I'd rewrite this rule as it seems a bit cumbersome and unwieldy:
While discussion of the various cars tunes and the methods drivers use in testing as well as their reviews of said car tunes is encouraged, anything viewed as a personal attack on either the car tuner or the driver/reviewer may constitute grounds for disqualification/removal from the contest. Discussion of anything related to the contest is highly encouraged. Personal attacks and bickering/flaming will not be tolerated as this curtails the enjoyment of the community as a whole and could lead to the moderators steping in and closing the contest down. This can be an enjoyable experience for all of us and a possible learning experience. Let's have fun and be respectful of others.
I'd do something along these lines:
Driver feedback, both positive and negative, is strongly encouraged but in a constructive manner. Not all tunes work well for every driver. Personal attacks will not be tolerated and may result in penalties or disqualification at the discretion of the organizer and also may be subject to sanction by GTPlanet.