[Conrad Rossi]

In a nutshell, eBay’s search engine “learns” from the adds being posted which includes the user categories and plain text included in the description. Therefore, when some sellers “overload” their descriptions by adding key words not related to their listing to drive traffic to their listing, such us “Chevy” , the search engine learns it. That’s how you end up with the wrong results. You can usually see this in listings at the very bottom of the description, usually preceded by a huge while space.

eBay allows to use operators to be more specific and filter out results. Here’s an example:

"1935 ford" -(ad, "muscle machines", caricature,postcard,hallmark, revell, ertl,diecast, die cast, postcard,advertising, revel,shirt, t-shirt,1:43, 1:18, 1:25, 1/32, 1/24,1/18,1/64,cast, monogram)

This is to search for 1935 ford and exclude everything between the parenthesis. The exclusion operator is the hyphen. Each term is separated by commas.

Not justifying eBay only conveying how their search engine works. There are more nuances to it.