I've heard it a number of times when researching SEO, and I think I even heard Matt Cutts from Google talk about it in one of his SEO videos. It used to be a very popular way to stuff pages with keywords and they caught onto it very quickly.
It's amazing some of the lengths the Google algorithm will go to to spot hidden text. People have tried using very sneaky and clever javascript and yet Google still catches it because their parser executes it and understands exactly what it's doing. So one thing to bear in mind is that having the text the same color as the background is probably the easiest thing for Google to catch, whether you set the color in the HTML or in a CSS style.
Knowing Google, they probably go so far as to measure the contrast between text and background color. So if your background is $FFFF and your text is $FFFE, they're going to know that it's a very low contrast that is invisible to most people.
Honestly, I wouldn't worry too much about having that text visible It doesn't detract from the content and people are used to seeing some kind of small print at the bottom of the page. Besides, it's actually relevant content. You have a page which is for a particular brand of car, and you're just clarifying which models that brand encompasses. It's not as if it's a nonsensical list of keywords. But yeah, it's probably going to look better in a lighter color than the main content...just not
too much lighter.
One thing I came to terms with through designing a couple of sites over the years is that there is always a trade-off between your ideal design and SEO considerations. It affects the style of your copy and also the layout. Your SEO optimized page is never going to look or read exactly how you'd prefer in the absence of SEO. The art is to balance the two so that you get good ranking while at the same time making sense to the visitor.