I agree. I prefer the plastic lens shades. They're lighter and they don't dent if dropped or smacked into something. I sold my metal shades for ridiculous prices people were willing to pay ($75 and up for some). The main thing to remember is don't buy new because that's where you get nailed by Leica.
Wetzlar M6, M4-P, 0 (Null) Series, IIIa, IIIc, 35 & 50 Summicron-M, 35/1.2 Nokton-M, 35 Elmar times two, 35 Summaron times two, 35 Jupiter 12, 135 Hektor times two, R3, R5, 21 Super Angulon-R, 35 Elmarit-R, 50 Summicron-R, 90 Elmarit-R, 180 Elmar-R, 280 Telyt. Contax G1 & 35/2 Planar.