I just have a couple of questions. First is do women have high heels that have lights that flash? I don't know because I don't keep up with fashion. Second did the Quantum Leap invent experimental cars with helping Sam invent his time machine? If not, where did Al get his experimental model car?
The present day of the series, where Al and Project Quantum Leap are set, were always meant to be "the future," relative to when the show was airing. By the 4th season they narrowed it down to late 1999, but then in season 5 it was not only still 1999, but earlier in 1999 - so they either had a continuity gaff there, or Sam had non-linear contact with the project as he leapt around through time (which isn't implausible.)
Women, to my knowledge, have never had heels with flashing lights; though by the late 90s, early aughts, children's shoes did...
Ostensibly Al's car wasn't strictly a fringe benefit of the project he was currently working on; he had been involved with other top secret projects, had a strong mind for engineering and was close friends to genius Sam Becket, so there are many ways Al could have his souped-up car.
"Our families are in there! Our, uh, mothers and... and tiny, tiny babies!"
I remember kids having flashing shoes by the late 1980's because I bought them for a kid I was babysitting. He'd practically fall over trying to watch the shoes while he was walking tho!!