Ok i managed to find where the sounds are located if anyone else is interested.

Savestra (closest thing to sounding like a rotary)

update\x64\dlcpacks\mpchristmas2017\dlc.rpf\x64\audio\sfx\dlc_christmas2017\savestra.awc

Elegy Retro

update\x64\dlcpacks\mpimportexport\dlc.rpf\x64\audio\sfx\dlc_importexport\elegy.awc

Sultan RS

update\x64\dlcpacks\mpjanuary2016\dlc.rpf\x64\audio\sfx\dlc_ja16\sports_saloon_4_jp_flat4.awc