The new map editor has it's problems. Main one being the test race function, what a fuck up by MTA.
That's the problem with MTA, they complicate everything so much, players just say fuck that shit. MTA, the game for coders.
I suggest map the checkpoints, but don't rely on them when testing, use your memory to remember where the race goes.
Bad system, but that's MTA for you.
Good thing about the new editor is the fine adjustments, you can fine tune each object position, unlike the old editor, where you has to keep upping and downing the object till you get the right position.
Also, the objects are streamed, thus meaning thousands of objects. (Ideal for your quality rally map).