purchased from the dealer. They are pretty reasonable and sell it by the foot. I have not had any problem with the milk jug color tubing but the majority of the black vacuum hose on my car was either cracked or split. All of the black vacuum hose under the dash looks good. I have even replaced some of the "X" and "Y" shaped rubber connectors too.
Jim
'85 300D
'95 E320
'97 CRV