kick the tires

Early 20th century. Tires on early automobiles were made of thin rubber and were sometimes of poor quality, hence a prospective buyer might kick them to see how thick they were or if they would deflate.

• "But, like the Color-Sonics machine, US operators have had no opportunity to "kick the tires" on Cine-Jukebox."
• "Red Flag 1: When an Analyst Doesn't Kick the Tires or Even Read a Company's Filings"
• "Microsoft finally took some of the wraps off last week, releasing Vista's first major test version to about 500,000 programmers and tech professionals. The goal is to let them kick the tires, run their software on it and provide feedback."
• ""Iowa has, the last number of presidential cycles, really been the bellwether state to pick nominees," he said. "And it's got this great balance of rural and somewhat urban, Midwest and Upper Midwest — it's just got a great balance of people so that the rest of the country looks at it. Plus it's a small enough population in size that people get the individual feel of candidates. It's like everybody depends on Iowa to kick the tires on the candidates.""
• "In the coming weeks, Albertans will get a chance to kick the tires of the party leaders, their platforms and local candidates."
• "The Packers will kick the tires on two injured starters in preparation for the playoffs."
• "Not content with the advantage it gets when 39% of its customers kick the tires on the merchandise in someone else's showroom before buying from them, Amazon decided to go a little further."
• "Jeff Zients[…]comes in, and he’s a former Bain Capital guy. He has “Bain brain”: He wants to run the diagnostics. He wants to kick the tires. He wants to see: Is this a good idea?"
• "Are you planning on buying anything, or are you just here to kick the tires?"

• kick the wheels
• take for a spin
• put someone through their paces