From comments on the website, also picked up by Ars Technica:

When I worked at the EPA finding these defeat devices was “part of the job”. We never had any trouble with the Japanese but all the other manufacturers were doing highly suspect things. With microprocessor engine controls in every car it is very hard to find what is going on.

Once a VW was in the middle of failing a 100K mile driving test (pollution devices had to work for 100K miles) and suddenly caught fire so the test had to be restarted. EPA engineers joked they were sure they saw a broken “Molotov cocktail” on the road next to the car. There were some other VW shenanigans but they were too complicated to explain. I owned a VW at the time but it was falling apart constantly so I had no sympathy whatever for VW.

Chrysler got caught doing something like VW but was caught in testing so they paid a smaller fine.

Ford lied like crazy and the EPA director had a big photo over his desk of the million $ check for a fine they had to pay. They were also ordered to “behave cooperatively” as opposed to the snarling obnoxious behavior they had formerly exhibited.

I also caught Ford in a defeat device and had to write a memo to them asking for written info instead of the lying (but sooo friendly) PR guys they sent out. They never answered so my letter was used in court as proof that we had tried but they hadn’t cooperated.

GM was no better but they were cleverer so we couldn’t catch them in testing. Enforcement division out in the field got them.

Honestly, it was just an “EPA doesn’t tell US what to do” attitude – it would have been cheaper for them if they had followed the Japanese example and just made clean cars to begin with.”

And rattling around the Brit press, this statement from an insider carried by the Telegraph, similar quote in the Guardian:

“Former government advisor Greg Archer, of the Transport & Environment thinktank, said: “It is probably not limited to diesel and not limited to emissions. There has been a lot of anecdotal evidence about carmakers using these defeat devices.””

I always wondered how they could get over 100 HP per liter out of an unturboed engine and pass emissions… Before the government nails VW to the cross, we should investigate every manufacturer and maybe the EPA too.