An original owner's manual for a classic car can be a prized and high-priced collector's item, especially if it belongs in the glove box of a rare high-performance model. The manuals, which contain technical data and other information, often go missing as cars pass from one owner to the next. Replacing them can be difficult — and expensive.

On the popular Bring a Trailer classic car site, for example, a driver's manual for a 1967 Porsche 910 sold last year for $14,000 (car not included). Manuals for Ferraris and other classic cars have also sold for thousands of dollars on the site.

Porsche, which is nurturing a growing classic car division, may have just deflated the market for classic owner's manuals. The company said last week that owner's manuals for nearly every model of car it has ever made — more than 700 — are now back in print and available for $70 to $150. The books, exact reproductions of the originals, date as far back as 1952, when Porsches were little more than souped-up Volkswagens. The manuals and other Porsche classic items are available at classicshop.porsche.com.