Vehicle variant for add-on vehicles is ignored until applied twice

[rxyyy]

Describe the bug

Spawning an add-on vehicle (model requested with engineRequestModel) and setting any variants doesn't work as it does on vanilla vehicles. However, applying variants again with setVehicleVariant makes it work.

https://streamable.com/avxj3t

The vehicle from the video can be downloaded here. The variants used are 0, 255.

Steps to reproduce

1. Spawn any add-on vehicle created with engineRequestModel.
2. Call createVehicle with any two variants that the vehicle model has. In the video I use 0, 255.
3. Observe that variant variables are synchronized but the grille (variant 0 model) doesn't render until variants are applied again with setVehicleVariant.

Version

MTA:SA Server v1.7-untested-26841

Additional context

No response

Relevant log output

Security Policy

• I have read and understood the Security Policy and this issue is not security related.

[iManGaaX]

🤷

[rxyyy]

🤷

a.mp4

[iManGaaX]

I just discovered the issue; the variant numbers aren't actually being applied in createVehicle. i will work on fixing it now, then open a PR and link it to this issue

[iManGaaX]

What arguments are u passing into createVehicle?

[iManGaaX]

I tested this and it works fine with variants like createVehicle(579, 2071, 1273, 10.8, 0, 0, 0, "test", 0, 255), but if i remove 0, 255, it defaults to 255, 255 and doesn't apply any variant

[rxyyy]

255, 255 is intentionally not applying any variant, that's how it works. As described in the issue, I use 0, 255 and the subsequent call to getVehicleVariant shows the vehicle is indeed set to use those variants, it just doesn't render them until I call setVehicleVariant(vehicle, 0, 255).

[iManGaaX]

idk how that happens on your end, works fine for me

2026-09-10.22-20-26.mp4