While researching a part, I was in contact with a gentlemen who still has his 1966 Mustang Coupe which he purchased new. Still has his window stickers even... And here is what it says....
Mustang Hardtop...............................$2372.00 Base 289 2V V8 engine....... ............. 100.00 Cruise O Matic.............. ..................... 189.00 Backup Lights..................................... 10.70 Fordaire Conditioner........ .................... 283.20 (factory installed as opposed to dealer installed) Radio AM.................... ...................... 58.50 Deluxe Belts & Tint Glass.................... .... 38.45 Padded Visors..................................... 5.70 Visibility Group............ ........................ 36.60
695 x 14 WSW Tires............................. 33.90 Transportation.............. ...................... 75.25 Total................................................$3211.902 speed washer system was part of the "Visibility Group" which included remote left hand outside rearview mirror, without the Pony option, and day/night interior rearview mirror.