G'day FF
I have a 1998 DRB with the same type seats (not registered yet) and the Engineer has said because more than one person may drive it, the seats have to be adjustable. I am currently looking for some sliders to bolt to the bottom of the seats. Take a wander through some wrecking yards and look at the slide rails, there must be something amongst all the little cars that will suit. If I find something suitable soon I will let you know. My son has a set he took off some seats that he bought for his 4x4 that look like they will fit, but he has to remember to drop them off, which could take a while.
Regards
Garry