500 has normal car issues.. but the model specifically has common issues with the battery earth strap (disintegrates), rear hatch wiring loom (wires can break and short out), instrument console LED (inner part dies), door handle (the hinge between the plate and the handle itself can break) and gearbox (input shaft bearing and/or oil seal can die prematurely) and the radio aerial can leak/corrode and lose reception.
Otherwise, shocks, brakes, exhaust, rear axle beam/spring mounts, rear damper bushes, front suspension (drop links and ARB bushes, damper top mounts and the dampers themselves) and lower wishbone arms, DRL lights (get bashed and become "un-stuck" from the bumper), wheels get hammered and your wheel trims will likely be scuffed or missing...
Also check everywhere to make sure it's not "bent".. learner cars but easy to fix means they get crashed and bashed.. but not written off .. so they can collect multiple accident scars over the years. Tough as old boots though.
Ralf S.