Seems the basic Prius Two and Two Eco are pretty basic in features. I would like fog lights, blind spot monitoring, wireless charging, auto up/down windows, a spare tire (cant believe this can be a feature), the best stereo and softex seats. The lane keeping assist, rear cross traffic alert, automatic hi beams, adaptive cruise control, pedestrian collision warning, heads up display, and park assist would be nice but not necessary. The HUD would be nice though. Unfortunately for 2016 models some trims got some of these features while others didn't and some are part of packages that cant be put on certain trims. Guess I cant have my cake and eat it too. If I could get a Two Eco with all the features and packages I want that would be cool but it looks like I have to make a compromise between certain features only available on certain trims. Budget max is $18,500 but preferably closer to $15k, with no care about how many miles or if it has been in an accident so long as it was fixed to OEM specification, but cant be a salvage title. VS995 ?
The closest to your specification is a 2017 Three Touring (missing JBL audio and HUD). In terms of used, probably Three Touring as well. (Basically, only the Touring models have the LED foglights). HUD came with AT package (Three and Four). TSS-P is standard on Three and higher for 2016.
FWIW, the LED fog lights are totally wimpy and I only use mine to supplement the parking lights while driving. They are brighter than the front parking lights and can be seen by opposing traffic without the headlamps on. You should know that in UK my Business Edition (not exactly a 3) has 3 ultra bright LEDs co-located with the Fogs but much brighter.
