Why did winter hurt the performance of one Porsche we drove?

And what surprise did electric-car maker Tesla drop on us Wednesday morning?

This is our video look back at the Week In Reverse--right here at Green Car Reports--for the week ending on Friday, April 10, 2015.

Friday we wondered what the next Presidential limousine would look like if it were a Tesla electric car.

The heavily-armored black car is known as "The Beast," and there's a bidding process out for a new one. So what if it were electrically powered?

Thursday we interviewed famed car designer Gordon Murray about his latest project, a hyperefficient, lightweight city car with very low fuel consumption.

The Shell Project M concept will explore just how efficient future cars can be while retaining gasoline engines. It'll start road-testing this November.

Wednesday began with a bang: Tesla Motors unexpectedly replaced the base version of its Model S electric car with an updated entry-level "70D" model.

Breaking it down, the new base-model Tesla comes with dual-motor all-wheel drive, a larger battery pack--70 kilowatt-hours versus 60--and more range, 240 miles against 208 for the previous Model S 60.

It also has Supercharger DC quick-charging as standard, and the price is now $75,000.

On Tuesday, we reported on a weekend spent with our most expensive Green Car Reports test car ever. That would be the 2014 Porsche Panamera S E-Hybrid.

As befits any $130,000 luxury sport sedan, it was a pleasant car in which to cover more than 500 miles.

But its rated 16 miles of electric range turned to 9 miles in Northeastern winter weather, and we view it as a preview of an all-electric Porsche coming in three to five years.

Monday, we covered the first-ever auto-show press event put on by startup Elio Motors.

Founder Paul Elio showed off the latest prototype of his three-wheel, two-seat car--more accurately an enclosed motorcycle, or "autocycle."

He answered questions freely, noting that the company now has 41,000 deposits for its $6,800 vehicle--but we think Elio has some major challenges ahead.

Over the weekend, we finished up our coverage of last week's New York Auto Show with two video previews.

One was for the new and refined 2016 Chevrolet Spark minicar, the other for the all-new 2016 Smart ForTwo--the first complete redesign of the iconic two-seat city car since the late 1990s.

Finally, we looked at a Honda dealer in Seattle who totally upended his sales process--getting rid of commissioned sales people and promising one-hour turnaround for car buying.

He took the best from the customer-focused Tesla and Apple store concepts, including fixed prices--and there's no more separate financing guy to see after you're done haggling.

It was a rocky transition, and he learned a lot along the way. But his sales are now back to where they were before the big change.

And we're betting his new car-buying customers are a little happier too.

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