Green’s Dictionary of Slang

(US black) a very worn tyre; also attrib.

1980		Eble Campus Sl. Spring 4: maypop tires – worn, slick tires which could burst any time.
2001		Triples Forum 🌐 Next you’ll be telling us that the T160 handles better on the Firestone ‘maypop’ Wilderness tyres...hehehe.
2002		Church of the Ressurection 22 Mar. 🌐 The old pile of metal that rolled on precarious, MayPop tires wasn’t worth investing the time, effort or money to maintain [...] From the picture you can see that not much effort goes into making this road safe to travel, especially if you are driving a worthless heap on MayPop tires!