My local Napa now has (special order) Valvoline Synpower XL III C3 5w30 which also has the Porsche C30 and VW 507 on the spec sheet.
Made in the Netherlands, not that much info out there. Really good price for 5 gallons, $135 before tax which works out to $33.75 per 5 quarts (sticking with my earlier measurement). Looks like it is "common" in Europe. I feel like Total Quartz is worth the $2 more.
https://www.napaonline.com/en/p/VCA881058
https://www.valvolineeurope.com/english/...xl-iii_c3_5w-30
SynPower XL-III C3 Motor Oil
SAE Viscosity Grade 5W-30
Viscosity, mm2 /s @ 100 ºC. ASTM D-445 -- 11.9
Viscosity, mm2 /s @ 40 ºC. ASTM D-445 -- 68
Viscosity Index ASTM D-2270 -- 173
Viscosity, mPa.s –30°C.
ASTM D-5293 -- TBN, mg KOH/g ASTM D-2896 -- 6,2
Pour Point, ºC ASTM D-5949 -- -48ºC
Specific Gravity @ 15.6°C. ASTM D-4052 -- 0.852
Flash Point, COC, ºC. ASTM D-92 -- 214
Approvals
BMW LL-04
MB-Approval 229.51
Porsche C30
VW 50400/50700*
"Formulated for VW Euro 4 and 5 engines with
DPF technology (Diesel Particulate Filter).
The product replaces virtually all VW
specifications and is suitable for engines with
WIV system, for extra long drain intervals up
to 30.000 Km. or 2 years.
Can be used in modern VW, AUDI, Seat and
Skoda gasoline and diesel engines."