As the weather heated up in May, demand for sporty cars for the summer months spiked, contributing to a scarcity issue for some models.

The Porsche Cayman, in particular, was difficult to find for dealers.

That’s according to May’s installment of vehicle scarcity data that is provided monthly to Auto Remarketing from AutoTrader.com.

The Cayman took the top spot nationally for both scarcest CPO and used vehicle in May.

The CPO model also took the top spot in Philadelphia, moving up seven spots since April. The sporty CPO ride came in at No 2. in Los Angeles, where it was not even on the list in the month prior.

The used model also landed at No. 1 in the San Francisco-Oakland-San Jose designated market area, which is the same spot it held in April. 

The Porsche Boxster was also hard to find as spring wrapped up. The CPO model came in at No. 4 nationally, and it was not on the list the prior month.

It also appeared in three DMAs, landing at No. 2 in Philadelphia, No. 4 in Los Angeles and No. 10 in New York.

The used Boxster also landed on the national scarcity list, AutoTrader.com analysts pointed out, coming in at No. 7, up one spot from April.

 It also appeared on the lists in three DMAs, coming in at No. 1 in San Francisco-Oakland-San Jose, No. 7 in Chicago and No. 8 in Houston.

The Chevrolet Corvette was another model in high demand in May and the third high-end model to make both the national CPO and used scarcity lists.

The CPO model came in at No. 5 nationally, and the used model came in at No. 8 nationally.

 The CPO model also had notable scarcity across several DMAs, including Dallas-Ft. Worth, Philadelphia, Washington, D.C., Chicago and Houston.

 “As a sign that summer is here, the Porsche Cayman, Porsche Boxster and Chevrolet Corvette are luring more online shoppers. The strength of Porsche continues with strong demand for the beautifully styled Cayman and the competitively priced Boxster,” said Juan Flores, director of operations for AutoTrader.com’s Trade-In Marketplace. “With the redesigned Stingray putting Corvette back into the spotlight in recent months, pre-owned Corvettes are experiencing a halo effect of the hype and excitement around the new model.”  

As construction rates move on at a consistent pace, big trucks were in high demand in May, as well.

Interestingly, Flores pointed out demand is high, but there is a catch: low supply.

“The challenge for the full-size truck segment is not due to lack of consumer interest, but more-so for lack of inventory in the metro markets. What’s interesting and significant is that heavy duty trucks have made our scarcity list,” said Flores. “This is clearly a sign that validates higher resale values for the ever important full-size truck segment.”

Here’s how the scarcity lists broke down for these models:

• The CPO Ford F-350 came in at No. 6 in Philadelphia, up one spot from April.
• The CPO Ford F-250 came in at No. 7 in Los Angeles and No. 8 in Washington, D.C.; it was not on the list in either of those DMAs in April.
• The Used Ford F-250 came in at No. 10 in San Francisco-Oakland-San Jose. It was not on the list in that DMA in April.
• The CPO GMC Canyon came in at No. 10 in Philadelphia. It was not on the list in that DMA in April.
• The Used GMC Sierra 3500 came in at No. 5 in New York. It was not on the list in that DMA in April.
• The Used Ram 2500 came in at No. 6 in Boston, up three spots since April.
• The CPO Ram 1500 came in at No. 9 in San Francisco-Oakland-San Jose. It was not on the list in that DMA in April.
• The CPO Chevrolet Colorado came in at No. 8 in Chicago. It was not on the list in that DMA in April.

Click below to view the complete scarcity charts for May from AutoTrader.com: