Welcome to Exhaust Notes, our self-titled, semiregular roundup of automotive bits and pieces from around the Web. Unlike other posts on this blog, these are truly notes -- stories too short to deserve a full post but worth a few moments of your precious time.

This week, the feds call for a mileage tax and don't take it back, GM is reuniting with Isuzu, and journalists stare at a driverless Audi A7 parking itself in Las Vegas.


Ready to be charged by the mile?


In February 2009, Transportation Secretary Ray LaHood shot off a zinger that immediately got zapped by the White House. LaHood had suggested a federal mileage tax that would allow the government to track odometer readings and send an automated bill to every American driver. That's not exactly what he said, but it's exactly what he meant. One day after he was quoted suggesting the tax, former White House press secretary Robert Gibbs said charging drivers by the mile "is not and will not be the policy of the Obama administration."

Well, nearly four years later, that doesn't seem to be the case anymore. LaHood is quiet, but now the Government Accountability Office is in full favor of levying a tax ranging from 0.9 cents to 2.2 cents per mile. The problem, says the GAO, is the declining highway budget that needs $110 billion to stay afloat in the next nine years. A bigger problem is that all of the fuel-efficient cars we're buying -- which is what the government had wanted us to do in the first place with the toughest CAFE laws on record -- have resulted in less money being collected through federal fuel taxes.

But according to the GAO, the only way to save our highways is to enact this new tax, or increase the gas tax -- which hasn't been raised since 1993 -- to at least 31.6 cents per gallon. Joy!

A new GM-Isuzu pickup?


According to Automotive News, General Motors and former Japanese partner Isuzu are working together on a new pickup truck. GM had a near-half stake in Isuzu until 2006, and in 2008, Isuzu quit the U.S. market. The current Chevrolet Colorado and GMC Canyon midsize trucks were developed in conjunction with Isuzu (also known as the i-Series, shown above).

We're not sure how to interpret the news. GM has already released a new generation of Colorado pickups, which won't debut in the U.S. for at least another year, with Isuzu (sold in Europe as the D-Max). Does this mean the U.S. will receive a new GM-Isuzu truck, or would it only be reserved for foreign markets? Neither company will say, but don't bet on Isuzu's extended powertrain warranties to return here.

An end to valets as know them?


Within three years, Massachusetts will eliminate all toll collectors as it rolls out a fully automated system. But toll collectors, like land-line phone workers and newspaper pressmen, aren't the only ones whose jobs are threatened by technology. Valets might be next.

At the 2013 Consumer Electronics Show in Las Vegas this week, Audi showed off an A7 parking itself. This wasn't an automatic parallel-parking feature as seen on many other luxury cars, but an autonomous car that can pull away from the curbside, drive itself to the parking garage and find its own space. No more worries that the 20-something guy getting into your $70,000 Audi will do a burnout on the next block, nick your rims, move your seat or rummage through your belongings.

But if that does happen, will Audi take responsibility? What if someone blocks the car's path -- which causes it to stop -- and proceeds to steal it? No one answered those questions.

Our suggestion: Stick with real, breathing, professional valets who work full-time at hotels and other venues. Third-party companies, which are contracted by several locations at the same time, have less of an incentive to keep your car in one piece -- or one place.