Petrol price increase has been slow during decades, even if taxes are very important on gasoline and diesel. Depending on travel we chose the best way : car, bus, train, plane... These taxes are effectively used (at least in part) to build and improve public transportation and highways. As the system is more and more capitalistic, even public transportation has to be profitable, and usefulness isn't a parameter anymore. Added to recent fast petrol price increase, the MPG problem becomes predominant for more and more people.
As in the US, there is a lot of different situations. During 5 years, living in Paris, I drove 0 miles and I used the train to visit my family. Then I moved near Toulouse and used the bus daily, while I used the car during week-ends and to visit my family. Then I moved more far from Toulouse and the bus wasn't an option anymore and no train was near enough to be an option, so now I'm using my car everyday...
Some people are driving all day long, but I think European are driving less than American. Not only because public transportation may be more developed, but also because our countries are smaller and so are traveled distances.
About regs on emissions & safety, I don't know who (EU/US) has the stricter and comparing them would be difficult as there is different limitations and these are measured differently.
About the fact European cars are more fuel-efficient than in past is because the constructors had to resolve the emissions restrictions, at least during the last decade. Before that the diesel was cheaper because it had less taxes (this is always the case but now gasoline and diesel are roughly the same price) to help petrol companies to sell more diesel, so car constructors sold more diesel, emissions restrictions became stricter and car constructors made more fuel-efficient cars.
I just looked at honda.fr all the civic models but none has rear wheel skirts. Since a few weeks I'm looking at cars in the streets and I have seen none with rear wheel skirts and only a few new cars has partial grill block (C2 [IIRC] from Citroen are the most present). But more and more cars has the look of a prius (per ex. C4 from Citroen, some Honda, some Ford...).
EU do not have rear wheel skirt and partial block grill generalized because fuel efficiency wasn't a parameter when choosing a new car. Now this parameter begins to be important but this is certainly (at least in France) because we have eco-taxes based on CO2 emissions and because the less polluting cars are also the more efficient, so these one are more and more sold.
<grunt>why no french car constructor has an hybrid, and why do we have only the prius since last year, the civic hybrid since this year and no other hybrid sold in France ??? Ooops I'm forgetting the LPG has partial tax suppression since more than a decade...
</grunt>
Since 4 years there is more and more automatic radars on French roads. Some people are always driving as fast as before, but a lot slowed down. They did it not to be safe, but to not get tickets and to keep points on their driving license... At the same time there has been a lot of pollution alerts, accompanied with temporary slower speed limitations. People has now associated speed with pollution.
Because there is now eco-taxes in France changing the cost of cars, people will associate consumption with pollution and the mentality will change durably.
I don't think petrol price fluctuation will change mentality. A few will change temporarily when price is high, but majority will quickly forget.
This is a durable change in my life that made me changed my mentality : the birth of my son
Denis.