FYI: Solar-powered race cars can go 88km/h: https://newsroom.unsw.edu.au/news/science-technology/world%C...

Having said that, if you throw in the required safety features and basic creature comforts of a modern car that's going to add a lot of weight but I wouldn't be surprised if such a purely solar-powered car could reach ~30MPH (with a 0-30 time of like 30 seconds =)

With the right balance of batteries-to-weight I wouldn't be surprised if you only needed to charge the car for like 8 hours to get 100 miles of range at highway driving speeds (on a sunny day with solar assist). The 1000-mile range is probably only possible if you're doing like 30MPH with the wind at your back with the sun beating down the entire time.