The article isn't suggesting using car models as a metric- it's suggesting using income.
No, I wouldn't advocate giving someone a fatter ticket because they're driving a ferrari instead of a camry. I would advocate giving someone a fatter ticket for being a millionaire, though.
And,in the current set-up with flat-rate tickets, the fine really isn't the same. Brad Pitt and I both get pulled over tomorrow for doing 65 in a 50mph zone- we're both given a $70 ticket. That isn't an "equal" punishment, because $70 is 20% of my weekly income while Brad Pitt gives $70 tips at McDonalds.
edit- Wow. Got ninja'd super hard.
Double edit- I'd like to clarify that I only support this up to a point though. Something like 50,000 bucks for a speeding ticket is obscene even if you're Bill Gates. In addition to making citations a percentage, I'd also throw in a hard cap. So something like, "X% of your income, or up to $2000", etc