= Solution
At the \b[magnetic equator], the inducing <magnetic field> and induced <magnetic moment> are horizontal. Let $x$ point along this field, approximately magnetic north, and $y$ across it. Directly over the car, the dipole field opposes the main field, producing a negative central <total-field magnetic anomaly>. A north–south traverse through the car gives
$$
\Delta T(x)\propto\frac{2x^2-h^2}{(x^2+h^2)^{5/2}},
$$
a symmetric central low with positive shoulders. An east–west traverse through the car instead has $\Delta T(y)\propto-(y^2+h^2)^{-3/2}$, a single negative trough. The equatorial anomaly therefore needs a stated traverse orientation; there is no universal single equatorial line profile.
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