docs(vehicle): record the axle flip did not fix the reverse direction

Flipping the wheel-bone axles inward->outward and re-importing left the drive
direction unchanged (-2788 vs -2680 cm/s). Reverted. The next probe is
SetThrottleInput(-1) to split throttle-inverted from wheel-spin-inverted.

MEMORY.md

@@ -1038,3 +1038,13 @@ Historical task context from 2026-11-09/10; later vehicle findings above may sup
   build_physics_asset(skel, dest, "PA_Vehicle_Sedan")` from a commandlet; the
   delete+recreate fragility earlier was really this missing `PhysicsType`, not the box
   centre (both −18 and +32.4 had the same unsimulated body).
+
+## 2026-11-10 — Vehicle drives backwards; the axle flip did not fix it
+
+- The reverse direction is not the wheel-bone axle sign. Flipping the axles from inward to
+  outward (`y - copysign` → `y + copysign` in `vehicle_build.py`) and re-importing changed
+  nothing (`speed=-2788 cm/s` still, vs −2680 before). Reverted.
+- Remaining suspects, in order: the Chaos wheel's spin axis convention (maybe it spins about
+  X, not the bone's Y), the engine torque sign, or the throttle sign. Next probe: run the
+  `-drivetest` with `SetThrottleInput(-1.0)` to split "throttle inverted" from "wheel spin
+  inverted" in one run.