  In this article, we show that a Finsler--Laplacian introduced previously can
detect changes in the Finsler metric that the marked length spectrum cannot. We
also construct examples of non-reversible Finsler metrics in negative curvature
such that $4\lambda_1 > h^2$, where $\lambda_1$ is the bottom of the
$L^2$-spectrum and $h$ the topological entropy of the flow.
