+1 some Motown, not a big fan (or anything that could be described as a fan-like) but it plays well loud, jv speaks truth.
Also dub/reggae is made for loud. Yet again, OP was narrowly specific in request as to genre.
Staying marginally OT, all the following (and for differing reasons) sound AMAZAHN when bending the car speakers, IMO:
The Field – ‘Is This Power’
British Sea Power- ‘A Trip Out’
James Brown – ‘Soul Power (live)
The Four Owls – ‘Silent Flight’
Sonic Youth – ‘Sugar Kane’
Leftfield – ‘Song of Life’
Joe Walsh – ‘Rocky Mountain Way
The Who – ‘Baba O’Reilly’
Pharaoh Overlord – ‘Black Horse’
My Morning Jacket – ‘Holding on to Black Metal’
Underworld – ‘Rez’
Today in the sun? Got to be Patti Labelle’s ‘Lady Marmalade’ up in yr boom-room or I swear you’re missing out