Many thanks for your input guys!.@Nils Pipenbrinck
The trick to get the movement right was to stay away from forces but express the physics in terms of energy instead. We calculated the kinetic and potential energy of each car on it's own and used the average energy to calculate the velocity of the car-group at each timestamp. This averaging made sure all cars move at the same pace along the path.
Hmmm..this is going to COMPLETELY change the way I have been doing things. It's an interesting idea Nils and I'll investigate more.@z80
If what I said is too abstract then you should probably give us some details about how you're doing things and we will be able to give you more specific guidelines.
I currently have a little mathematical model which approximates the acceleration, I then numerically integrate at each timestep which gives me all the information that I need to place the car at the correct position and make the simulation realistic.
Just a thought here: couldn't I maybe do the same with the acceleration?. Calculate the acceleration at each timestep and average these out and from that get my velocity and positions?. My thinking here is that if the same force is acting on each car, it should in theory have the same velocity and positional change.
Nils, any chance you could provide a link to that animation?. Thanks man.