Mercedes AMG S-63 has been spotted testing with minimal camouflage. The global reveal of the AMG version will happen later this year. The spy shots indicate reworked bumpers, quad exhaust, bigger wheels and the signature Panamericana grille, exclusive to AMG variants. On the inside, the S-63 could get new carbon-fibre elements, sporty seats and an AMG steering wheel. It is expected to be powered by a 4-cylinder V8 engine producing around 700bhp.