10 inch spider near Mexico City
It almost definitely wasn't 10 inches, but there are some pretty big spiders in Mexico. There is a species of spitting spider with a 9 inch legspan but it lives in South America not Mexico.
Scytodes globula


The cellar spider has a legspan of up to 3.6 inches and a comparatively small body with long skinny legs and no visible hair, but I can't see how that would be confused for 10 inches.
Pholcus phalangioides

The giant crab spider fits that description to some degree. It has a legspan of up to 4 inches.
Heteropoda venatoria

The golden silk spider is very large with long skinny orange and red legs.
Trichonephila clavipes