Your car may be an XJR-S, although all of these had boot badging and
JaguarSport logo on the intake tracts.
All the bits you describe can be added aftermarket, so it may be a car that
someone has decked out to LOOK like an XJR-S.
Hong Kong cars are always suspect in the antipodes (ie Aust/NZ) especially
if their earlier provenance is not known; many such that have found their
way to Aust are in fact ex-UK cars that have spent only a year or two in HK
and are full of slush-and-salt-road-induced terminal rust. Many Aust.
purchasers have taken delivery of such unroadworthy, unregisterable cars,
having paid for them, plus the duty, shipping costs, insurance and all, in
the erroneous belief that the car had had a Hong Kong life.
Still, it may not be such a car, and good luck to you if so, as the TWR
bodykits are expensive and probably difficult to obtain now.
Headlight washers and wipers were a standard fitting on XJ-Ss from about
1987-91, and they work (via a complex system of relays and wiring) whenever
the windscreen wipers are activated and the headlamps are on.
Hope this helps,
former XJ-S owner and nutcase about them!