the only time you need to be concerned about plastic versus rubber is where the lines are located. Are they next to hot parts on the engine or inside the car for say door vacuum. I.D. only matters when volume is a concern. If its tight and does'nt leak the I say its good to go. Just my 2 Cents

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DRIVE HARD-DRIVE FAST-DRIVE TO GET THE HELL OUT OF MY WAY.

1986 190E 2.3-16 Pearl Black!!
1987 190E 2.3-16 Smoke Silver!!
1986 190E 2.5-16 Pearl Black!!
2004 CLK 500 Cabrio Designo package!!
1994 E320 Cabrio Red with black top!!
1985 500 SEL Anthracite Grey !!
2011 Subaru Impreza STI 380HP (Yeah Baby)