Been doing some research on Manual Transmission sales.

In 2013, I was able to estimate that around only 608,400 vehicles in the US were sold with a manual transmission.  That may seem like a lot, but in 2013, car sales in the US were an estimated total of 15.6M.  So in percentage perspective, that's only 3.9%.

Their might be some miscalculations in the numbers however because in the first article I've read, it said "as of August, 2013" and the other article that said the yearly sales figures for the whole year of 2013.  Also it did not say in the first article whether if the percentage was from US sales or Worldwide sales.  But if the percentage stayed around the same and was US sales only (I'm assuming it's US sales only as it's from Edmunds), the total amount of manual gearbox equipped vehicles would be around 608,400-maybe 700,000 out of 15.6M new vehicles in America for 2013.

My Sources:
http://www.edmunds.com/fuel-economy/five-myths-about-stick-shifts.html
http://www.nydailynews.com/autos/auto-sales-reach-six-year-high-demand-peaked-article-1.1567645

To me however, it seems rather unfair to come up with a percentage using every vehicle sold for the whole year because some vehicles don't even offer a manual transmission.

Fine examples of vehicles that don't or no longer offer a manual gearbox include:

• Certain Mid-Size Cars and most Large Cars
• The majority of all Luxury Cars
• Big SUVs and Crossovers
• Exotic Sports Cars like Ferrari, Lamborghini, McLaren, etc. (they switched to flappy paddles).

Examples of vehicles that you can still get with a manual gearbox:

• Most Minicompact vehicles (like the Fiat 500 or the Mini Cooper)
• Most Subcompact and Compact vehicles
• Entry-level and Non-exotic Sports Cars (like the Mazda MX-5 Miata or the Corvette)
• Pony Cars (there's only three, the Mustang, the Camaro, and the Challenger)
• And surprisingly, the Jeep Wrangler

But my point is with the amount of vehicles sold that don't offer a manual transmission where popular models include the Ford F-150, the Chevrolet Tahoe/Suburban, Luxury Vehicles that people with money like to buy it only makes the percentage of manual gearbox sales smaller.  People who write reviews and news articles should compare specific makes and models that offer both manual and automatic gearboxes and then make percentage figures with that.  For example, the Ford Focus or the VW Jetta and Golf would be fine cars to compare transmission sales with.