http://rcnewz.com/?p=5283
The after market is doing good job with this for the 201. And the Vega for mid motor.
more and more upgrades are available for the 502. I don't think there will be another belt driven 4wd to continue the 511 legacy. I have to admit though, it's a great car and still a winning design. Maybe they should just relelase another round of 511's.