ETS 08-21 Subaru STI Top Mount Intercooler

This 21-by-7-by-4-inch top mount gives the 2008–2021 STI more charge-air cooling while keeping the short factory pipe route. I'd choose it for a responsive street build that needs more heat-transfer capacity without a front mount conversion.

It installs without moving the rear A/C line and uses studs for the valve mounting. It still depends on hood-scoop airflow and remains exposed to engine-bay heat. ETS specifies that it does not fit the 2008–2014 WRX. Anodized cast end tanks can show uneven color.