BusinessTechnology -- The Mexican waveAt long last, Mexico is enjoying a startup bonanza.Kavak, a Mexican startup, provides an elegant solution to a glaring problem: how to buy a used vehicle in a market that is both one of the world’s biggest and its most informal second-hand car markets.Few buyers trust a seller’s assessment of the good’s quality.Few sellers trust the buyer to cough up the money.Transactions often involve “meeting someone at a corner store and seeing how it goes”, says Alejandro Guerra, Kavak’s general manager in Mexico.On Kavak’s app people can buy and sell cars with the company acting as a trusted middleman.Kavak, which last month raised $700m in a funding round that valued it at $8.7bn, is part of a startup explosion in Mexico.Since the firm became the first Mexican startup to be valued at more than $1bn last year it has been joined by three more such “unicorns”.So far this year unlisted Mexican tech firms have raised nearly $3bn, roughly as much as in the previous nine years combined.Mexico’s 126m people are on average young and almost in the upper-middle-income bracket.Some 54% own a smartphone, according to Newzoo, a research firm, a slightly higher share than among similarly novelty-loving Brazilians.