The problem isn't collisions bud, it's when you have so called team mates ramming you wide at checkpoints because they want to win. So many people still don't realise it's a team event. I'm more than happy to come home 4th, 5th or 6th as long as I'm helping the team win. Why challenge my team mates in front if I can keep the A.I cars behind me?
As for if you need meta-build cars bud, no. As long as your car is competitive you'll be fine. Next season the Trial events are all for base models anyway.