Okay, this is really good. It feels just like the arcade, and you can even pass through the red cars at the very start of the level just like the arcade (a key strat) - I was stunned that it worked here! Honestly, I love that the play area is "zoomed out" compared to the very claustrophobic original, and I don't mind the flag/rock placement being, for lack of a better term, randomer (although I did get a flag in a one-tile dead end as a result...).
I do have to ping you on two big things, though. First, you're using the original Rally-X's maps instead of New's, aren't you? Your own second screenshot on this page gives you away - New Rally-X has a gap near to the right of where the player car is, making that infamous Room of Death no longer a dead end. Second, you have the Lucky flag blinking on the minimap rather than the Special flag. If that was an intentional decision, it's a bad one, as it removes the luck from the Lucky and the strategy from the Special; if it's an oversight, it's a huge one, especially given the attention to detail the rest of this version has. I strongly suggest you consider that a bug and fix it right away (I'm guessing finding the map alterations will take longer).