Back in stock, exclusively for Prime members:
Amazon offers Castrol 03057 GTX MAGNATEC 5W-30 Full Synthetic Motor Oil, 5 Quart for one-time purchase price of $17.88 with free Prime shipping or for $15.20 with Subscribe & Save.
Amazon has Castrol 03060 GTX MAGNATEC 0W-20 Full Synthetic Motor Oil, 5 Quart for $19.88 one-time purchase with free Prime shipping or for $16.90 with Subscribe & Save.
Amazon also has Castrol 03063 GTX MAGNATEC 5W-20 Full Synthetic Motor Oil, 5 Quart for $17.88 with free Prime shipping, but S&S discount is currently not offered.