It's that time again, our regular roundup of last month's most popular posts on GreenCarReports.com. For May, we have some new contenders as well as some recurring regulars. Here we go:

# 1: Ferrari To Go Hybrid, World Trembles On Its Axis.  Sometimes one of our entries catches fire on Digg, and that's what happened here. It's the second most popular piece we've ever run. Bottom Line: Even Italian sports cars are looking at using hybrids to improve their efficiency, including Ferrari, which plans to launch a hybrid system in at least one model by 2015.

# 2: BREAKING: House Agrees on Cash-For-Clunkers Bill. Falling just one notch, this news item was our best effort at the time to detail the (still incomplete) compromise Cash-for-Clunkers bill that the US House of Representatives apparently agreed to--though there are likely to be further gyrations before any legislation is approved. Bottom Line: Old vehicles traded in must achieve combined EPA ratings of 18 mpg or worse, and their replacements must come in at 22 mpg or better. The largest tax credit ($4,500) is granted for the highest improvement in fuel economy. Cars, light trucks, and other commercial vehicles have separate rules.

# 3: Pollution Perspective: One Giant Cargo Ship Emits As Much As 50 MILLION Cars. This six-week-old piece continues to circulate, meaning that many people really didn't know that the world's cargo ships emit so much uncontrolled airborne pollutants that they post a much, much greater risk to air quality than vehicles. Bottom Line: Just a single cargo ship of the largest class now on the seas emits as much every year as 50 million vehicles do. One reason: The fuel they burn is equivalent of liquid asphalt.

# 4: Will the 2010 Volkswagen Golf TDI Be Diesel's Biggest Winner? Our dedicated diesel drivers come through again, launching this latest installment in our coverage of clean diesels toward the top of our chart. Bottom Line: We think that Audi, BMW, and other brands that haven't previously sold diesels in the US will have a tough time getting a foothold, while Volkswagen will benefit from its low prices and that same loyal band of diesel owners who already know the cars' benefits.

# 5: The New 2010 Rabbit TDI Diesel...Or, Is It a Golf Again? Now 10 weeks old, this perennial top-five post tags right onto the previous item. As we've said, we love our Veedub diesel fanboys. Bottom Line: Never mind the PR waffling from VW spokeman Steve Keyes, we got it right the first time. Yes, the 2010 Volkswagen Golf won't be a Rabbit after all. Snap!

VWvortex reader Bajan2.0T snapped this shot of the badges on the 2010 Golf TDI that was displayed at the Toronto Auto Show.

VWvortex reader Bajan2.0T snapped this shot of the badges on the 2010 Golf TDI that was displayed at the Toronto Auto Show.