Hi,
From what I've seen the UK S2 & TC/TCS cars had a single wiper. The US (Federal) ones had 2 wipers, which probably didn't look as cool but no doubt worked far better !
On the speedo cable path, mine is a TC car and when I changed the chassis I routed it along the rear legs of the chassis & through the central spine. I can't remember if that's where it went or not, but that's the way it goes now !
Brian