" subtle " would be a retro PORSCHE script decal along the lower sides ...not late 60s era Gulf or late 70s era Martini Racing livery style graphics on a current daily driver looking 991 , imho . Even on the uber 918 ...it looks a bit over the top , not just in pics but actually more so in person from my attendance at the Rennsport Reunion V back in Sept

my suggestion for retro would be this Singer -style two tone one of the classic side graphic , but with silver grey striping giving a " subtle " but sophisticated tone-on-tone effect with your platinum silver car ....with only the black lettering standing out ...much less " in your face " than the typical all-black version as seen on the 987 Boxster Spyder

an additional benefit of this two tone combo is that it looks good whether one has oem silver , platinum or black wheels