Category 1: Parent or grandparent of a boy between the ages of 2-5. Your first thoughts were probably along the lines of: "there are BOOKS about Lightning McQueen? Really? Where can I get them? Is rush shipping available?"
Category 2: Everyone else. You probably asked yourself: "who is Lightning McQueen?"
For those of you who fall into the first category, yes, there are books about Lightning McQueen. See the specifics below. And for those of you in the second category, he's the main character in the Pixar movie Cars. Here's a picture of him:

I've done some informal observation and have found that just about every little boy I've met is obsessed with this movie. I think it's for two reasons. One, it's about cars. (I guess that's rather obvious from the title). Two, it doesn't have any scary parts. (If you think that's also obvious because it's a movie for kids, then you probably haven't watched a lot of kids' movies lately. Almost all of them have inexplicably scary parts).
Please keep in mind that I'm recommending the books below only for Cars-crazed kids. I'm not endorsing them as good literature, but here are some resources if you're looking for them. I usually hate this kind of commercial stuff, but I also recognize that sometimes a kid just wants to read about something they're interested in. And, the important thing is that they're reading.
Disclaimers aside, here are the (relatively) good books I've found on the subject. And, yes, I'm the parent of a Cars addict.
Old, New, Red, Blue! This is a basic opposites book using the Cars characters, and it's a good choice for the 2-3 year old crowd. There are only a few words per page, which is just right for that age range. It's a small paperback so it travels well. I highly recommend it.
Cars Little Golden Book: This book retells the movie. The paragraphs are a bit too long, but the illustrations of the various cars (which is really all my son is interested in) are pretty good. My main quibble with this book is that it cuts off the story well before the ending and doesn't include the all important final race.
Cars Ultimate Sticker Book: DK has tons of sticker books, and this one is fairly typical. I think it has way too much text and it's a little advanced for the 2-3 year old age range. But, it has 60 stickers of Lightning McQueen and friends, and works well as a travel activity.
Cars Resuable Sticker Book: I like this sticker book better than the DK sticker book, because it has a lot more stickers. Plus, there are tons of activities. My main issue with it is that it's oversized and it's difficult to fit into a diaper bag, purse or backpack. Also, we found the stickers to be reusable only a few times each... after that they stopped working.
The Fast Lane: A basic coloring book featuring Cars characters. The pictures are large and easy to color. It's 64 pages, which is a good size for a coloring book.
Have you come across any other Cars books that you'd recommend or that your kids liked?
Have I lost all my credibility as a reviewer by writing this post?