Initial ideas:

The buggy has to have some holes at the bottom so that the LDRs can have detect the change in reflected light as it follows the black line.

However the problems that were going to rise was that the LDRs that were going to be at the bottom of the Chassis were going to be shielded from any kind of light.

A idea that was proposed by the programmer was the use of LEDs to provide a supplement light with the LDRs to be used but this idea was discarded at the end with the change in program which was supposed to sense the change in light and move accordingly.

Another problem with the design was the front wheel this had to be carefully thought as the front wheel was going to handle most of the weight and it was supposed to freely rotate at an angle of minimum 90 degrees.

Initial idea :

Using a ball bearing: