Vehicle NPC does not seem to be driving properly (repost)

(reposted because there was no one reading my thread)

i discussed in last thread about vehicle npc going hoppy when parented to workspace, but it was solved by me later

now speaking of recent problem i witnessed, while it works in not-my-game test place, there is something that seems to be off when i test in real game place. here are demonstrations:


the first type of npc: it doesn’t go through non collide part such as checkpoint even though the raycast has a list which contains blacklisted parts and models (it thinks the checkpoints are obstacles), plus it tries to reverse to the last node of track

the second type of npc: its heading and steering slightly improved. but its driving skill is still beyond the level of stupidity (driving around the circle, which often happens)

the third type of npc (which i borrowed from MSDLF): its driving is nearly perfect, but it struggles on avoiding obstacles and others kart. in some case, the npc also skips current node to another node, where is inaccessible for it

for this time, i expected to see it working like Kinnis97’s canceled racing game, roblox rally (shown below)

but it failed to meet my requirements. so what are the ways to make my npc become as smart as roblox rally’s? and here’s the file
ai_test.rbxl (129.4 KB)