So leaking/split windscreen washer pipes are probably the fault & will need to be replaced!
I think that Kin's Series III had the same problem.
This brought back some fond memories of my Aero owning days(mostly brilliant!

)
I did 10000miles in its first year, and must say that 99% of the time was dry conditions only, hence the use of my windscreen washers was extremely rare.
To cut a long story short..apparently everytime I uses my washer, not only did it squirted water onto my windscreen, it was also squirting water under the dash as well, later Perrennal(spelling?) garage found the washer piping was badly fitted and used inferior fittings(if my memory served me correctly)
The most unforgiving fault/build was both doors has no drain holes, so when it was parked outside SGT for sale, water were trapped inside both doors upto 6inches high, drowning all electronics and short circuiting most things

This left me slightly resentful towards MMC for such oversight! (Julian at SGT told me that another Aero had suffered the same fate) I believe alot of these issues should not have happened, if the factory paid a bit more attention to details.
Sorry if I offended some senior members on here

but I think MMC should stand up and be counted...
Having said all that, I would not hesitate to buy another Aero when the time comes.