What type of evidence are you looking for? There is lots of evidence, much of which you can find via googling. You can also find other threads on this board with other owners. You can see throughout this thread there are multiple owners who are visiting this thread to contribute a "I'm suffering from this issue also" comment.

As well, the service manager at my dealer has informed me that the high-pressure fuel pump on many 35ds that they have sold over the past year, has required replacement.

In short, yeah there's TON of evidence that many people are having his issue with their 35d.

Dozens? Yes. Hundreds? I'm unsure. But there is a fairly constant stream of folks with 35ds who are complaining of this issue happening to them.

As for the 335i, its a known issue, which you also find by googling or checking Bimmerfest. It's very easy to find "evidence" London Lad. I tend to believe that people don't go through the trouble of hiring an attorney or proceeding with a Lemon Law Return (which is a consumer protection law in the U.S.) unless there's an issue.

Both routes are VERY time consuming and take a great amount of effort and/or financial output. One 335i owner (on Bimmerfest), I found hired an attorney, after reaching the end of "his rope" and had his 335i replaced with an X5 4.8, with one letter, after having the "engine malfunction-reduced power" issue pop up multiple times, due to a faulty fuel pump that continued to fail.

What more are you looking for? Few disagree the issue exists. The disagreement is on how widespread it is within the 35d line.