Hi fellow benz enthusiasts, I have a 84 300DT that I've put aused three stack tank in left front wheel well behind plastic seal between fender and liner. I ran line to large green vac line thru check valve to boost climate control vacuum.also installed used large flat tank above fuel tank in trunk (yellow/gray)line for door locks, fuel door, and trunk lock. All the above worked more smoothly for me. Hope this info helps. bill (bubba)