I had the odd idea of setting up "overflow" parking sites that are distant from the shopping areas, but have "shuttles" to the places people want to go. (In theory like what is commonly done during the christmas shopping season).
In actuality this idea is to create parking unlike the parking that's typically near a business district. Typical businesses want to keep people from just leaving their cars, because they want to rotate in new customers. It might be interesting to set up an area that's well connected to the mass transit system and and has a pricing structure that encourages people to leave their car in one place, instead of how the current "park for x minutes" encourages people to keep driving their cars around.
The other clever part was that the thing you get when you park your car at this facility could be used as a bus pass on the local transit. Perhaps there could even be a bike station and bike routes nearby.
Bonus points if the information kiosks that show people how to get from this "spillover" lot also shows how to get to the interesting destinations without having ever needed to drive. (AKA it hints at the regional transit options).