There's a nest in the Landrover

Something went ker-phut with the starter motor last week so the Landie has been sit-satting there, no use to man nor beast.
Ummm, no, that's not true. Something likes stationary. It likes the convenience of a dashboard shelf. It likes being undisturbed by shake, rattle and roll. Beastie wants to make a nest, and beastie has.
No sign of life, but a very neat doughnut of soft leaves, straw, hay and moss has been formed. Is it a bird? Is it a mouse? One says former, others say t'other.
But now the Landie is fixed, so perhaps I'll never get to see the inhabitants.