A genuinely bulletproof body-on-frame SUV whose only real homework is the Takata airbag recall and a frame-rust check.

The 4Runner's body-on-frame steel rusts in salt-belt states, and mechanics are blunt that a rotten frame means walking away because replacing a frame costs more than the truck. Separately, the rear hatch develops rust under its plastic garnish trim — the trim vibrates and digs through the paint into the metal over time. A 2016 is old enough that a northern-climate example needs the frame inspected from underneath, not just a glance at the shiny body. A clean southern truck sidesteps this entirely.

A recurring 2016 complaint: rodents chew the wiring harness because Toyota's insulation is soy-based, taking out injector or knock-sensor wires. Owners report repair bills around $500 that warranty declined as rodent damage, not a defect. Toyota's own bulletin (a repair-versus-replace harness guide) acknowledges the damage pattern. It's a garaging and parking-habits issue rather than a mechanical weakness — but budget for it if the truck sits outside, and inspect the engine-bay harness on a car with any electrical gremlins.

Two separate things live here. Mechanics say the 4Runner's brakes simply feel soft and nose-dive by design — that's the truck, not a fault. But the front calipers (four pistons each) and slide pins seize in wet and salty climates, and the smaller rear pads wear fast, causing pull and warped rotors. The fix is maintenance: clean and lube the slide pins, flush the fluid, watch for uneven pad wear. Test it by braking hard from 30 mph with a light grip — a pull to one side flags a sticking caliper.

Some 4Runners finished in Blizzard Pearl (070) or Super White (040) shed factory paint as the primer fails, and 2016 complaints describe clear-coat bubbling on the hood and roof. Toyota runs Customer Support Program ZKG — a quiet, no-charge coverage program, essentially an extended paint warranty — to repaint affected vehicles. If a white or pearl 2016 shows peeling, that's a covered repair, not a flaw you eat. Confirm eligibility at a Toyota dealer.