Picked up some 3422 Bosch Premium filters today and noticed that the baseplates are stamped with the same numbers (3, 4 & 16) as on Premium Plus, PureONE & AA Total Grip filters. Has Purolator always made the Bosch Premium filters or is this just a result of the Bosch takeover? Except for cosmetics, the Bosch Premiums seem to be PureONE clones...with the exception of the gasket on the baseplate. Both claim 98% filtration efficiency, both have silicone ADBV's and both have the same bypass valve. Not a bad deal for $3 (on sale at CSK).