Wholesale used car prices hit a record high in September with the chip shortage and other supply constraints squeezing new-vehicle inventories and combining with strong demand to send prices soaring. The Manheim U.S. Used Vehicle Value Index rose 5.3 percent over the month in September and by 27.1 percent over the year to an all-time high reading of 204.8.  The index is one of several datapoints that provide a snapshot of trends in the secondhand car market, with Manheim being the world’s largest wholesaler of used vehicles. Wholesale prices paid by dealers typically end up getting passed on to consumers. At the end of August, the average list price for a previously-owned vehicle was nearly $26,000, according to Kelley Blue Book, while the most recent government data (pdf) showed that used car and truck prices were up 31.9 percent over the year in August. “When the Manheim Index hit a record high …