Which German car manufacturer makes the 718 Cayman?

Porsche makes the 718 Cayman.

The 718 Cayman is a two-seat, mid-engine fastback sports car produced by Porsche. It is the coupé counterpart to the 718 Boxster roadster, sharing much of its engineering while using a fixed roof for greater structural stiffness. The current 718 generation, internally known as the 982, was introduced in 2016.

The “718” name connects the modern Cayman to Porsche’s lightweight 718 racing car, which won the demanding Targa Florio in 1959 and 1960. The road-going 718 models initially used turbocharged, horizontally opposed four-cylinder engines; higher-performance versions such as the Cayman GT4 and GT4 RS used naturally aspirated flat-six engines.

A common mix-up is confusing Porsche with Volkswagen Group, which owns Porsche and supplies or shares some corporate technology across its brands. The Cayman itself, however, is a Porsche model. The name also refers to a caiman, a crocodilian, rather than to an engine or trim level.