Suggested

Back Markers

Back markers shouldn't be able to boost past faster cars. 100% be aloud to boost up to them to get drs but not overtake.

Are you talking about AI players or live players?

Does it really matter ?

Yes it matters cause AI is just luck / unluck (gotta live with it) so it would be a bad suggestion while live player would be imposing a rule of some sort on a live player so possible but difficult and / or controversial 

I don’t mind a back marker boosting ahead of me if it gives me an opportunity to gain DRS.  Of course it does matter where on track it occurs.  Mind you a live player behind me might not like it if it gives me an opportunity to pull further away from them and sometimes backmarkers can interfere with the race result.

What happens if a live backmarker boosts past you so that they can get behind a legitimate opponent.  Would that sort of a rule be a bit unfair on a manager legitimately racing against another whom is ahead of your car?  I would not wait for you to get past him, just because my doing that is annoying for you.  It would, in turn, be annoying for me and may lose me a legitimate advantage over an opponent.