Wind field. Rankine vortex: tangential speed vθ(r) = Vmax·r/R for r<R and Vmax·R/r outside; plus 25 % radial inflow and a Gaussian updraft Wmax = 0.5·Vmax that decays with r.
Forces on a vehicle. Quadratic drag F = ½ρCdA·vrel², ρ = 1.2 kg/m³, Cd = 1.2 (side); underbody lift ½ρClAtopv², Cl = 0.65; tyre friction μ = 0.7. The vehicle slides when drag exceeds μN, overturns when the wind moment about the wheels exceeds the weight moment (½·track·m·g), and lifts off when lift exceeds the weight.
Honest limits. Educational approximation: rigid body, no real aerodynamics of a car shape, no debris impacts, no turbulence, no sub-vortices. Real tornado winds vary a lot; this is not a damage predictor. Wind in the EF-scale is a 3-second gust estimate; here Vmax is a steady peak speed.
Check.
Models: Kenney Car Kit (CC0). Same equations drive the matching Unreal Engine video; Record exports the run as JSON for that renderer.