They are both. Allow me to explain.
The pickup truck is a fundamentally white invention. Aside from the obvious fact that it was created by and adopted by white men, it speaks to the very soul of the white man. It is large, it is boisterous, it is nearly essential for the white man's work and his leisure. Fishing, hunting, snowmobiling, dirt biking, and many more fundamentally white pastimes are made way easier by a pickup truck.
However, Mexicans are merely a poor imitation of the white man. Take a white man, and make him lesser in size, intelligence, and belief systems. What you are left with is a Mexican. There is nothing more fundamentally Mexican than copying the white man's works while adding your own twist to make it objectively worse. Where the white man has country music, the Mexican has mariachi. Where the white man has hamburgers, the Mexican has burritos. This is reflected with the Beanoid's migratory patterns. The highest aspiration of the Mexican is to move into the white man's country, and turn it into a lesser version of itself while acting as the permanent underling of the peckerwood. Thus, they also adopt the pickup truck. And true to form, they make it lesser with their trademark spicification. Where once was a bumper sticker, now is some duct tape holding the bumper together. Where once was a towing hook, now is a set of bull horns. Where once was a gun rack, now is a satchel of roofing tools. The Pygmy stature of the Mexican in relation to whitey is even reflected. Where once was a lift kit allowing Kyle to effortlessly pin 'er through a small bog, now is a lowering kit allowing Juan to reach the running boards despite his stubby little legs.