I've always viewed Readily Available as At the Time from a retailer, not as Always and Forever available. Otherwise, as with ASTs, when the company stops making that model, then that makes all previous ones sold illegal. Same if a company goes out of business, or is sold and changes the name. If Bilstein changes from a double nut to a nylock and thus change the part number, the old part number is now obsolete, all previous shocks are illegal? I don't think that's the intent.