I Love clams too but for sport, its better to see where the front wheel is tracking.
I have also heard of the clam tips being forced down. I can't verify that.
The Clams give the car that familiar MG TC look that complements the short boot as Lotus marketed the S2 as more of a road car, which carried over to the S4. This continued with Caterham well into the 80s until Cat introduced the cycles in fiberglass.
I can't think of any Lotus 7 S2 or 3 that had factory cycle wings. Once Lotus was done banging out alloy noses and fenders of the 6 and S1 Seven, that was it. GRP was cheaper to make, required less skill set and didn't need painting. Also, as these parts tend to get damaged easily, GRP makes a lot more sense.