It will likely be a very long time. Even though the sun's energy makes life on Earth possible, today's best solar panels money can buy are only around 35% efficient when it comes to capturing all the energy the sun emits. And even if we did have 100% efficient solar panels the general number for power density of sunlight is 1000W/m^2. If it were possible to harness all of that power, a typical sedan would have to run off 10-20 hp. This is far less than the consumer cars on the market.
But don't let that discourage you. Many of the technologies and innovations pushed by Solar Car Racing eventually make it to consumer cars. The new Toyota Prius includes a solar roof to power some of the auxiliary parts. All hybrid cars make use of regenerative braking. In Solar Car Racing, we strive for high efficiency wherever possible. In a consumer car, this equates to highly increased MPG (for an ICE car) or M/kWH (for an EV car).