Full Spead Ahead (1951) on Netflix

Plot summary

Luis Macías wants a friend he can trust, and Pedro Chávez, a drifter, is trying to get his life back on track. The two meet while Luis takes part in a tryout for Mexico City's traffic squad and Pedro watches from the sidelines. Luis has been taken advantage of before, but he gives the stranger a chance, and the men move in together. Luis places first and joins the unit, and Pedro, inspired, gets himself accepted too through nerve and persistence. Both ride well, and each goes after the rank of commander, to be decided at a big event at Plaza México weeks later. The contest spills into their home, where pranks and tricks keep them getting even.