Pretty much all Lagunas are keyless these days, but not sure how that affects the SL.

It's more likely the hydraulic power steering failed when the engine stoopped and he failed to account for the extra effort required to make the turn.

Errr, polyethylene terephthalate = PET. The stuff they make Coke bottles out of. Should be ok in most environments and it's cheap.

Teflon is poly(tetrafluoroethylene) which is very chemically stable and has excellent temperature resistance. However, even if it offered the same resistance to the high voltages in the system as the PET, it would probably make these things prohibitively expensive.