Download a free HDR image set from HDRI Hub
HDRI Hub has posted a free night HDRI set, intended particularly for use in automotive renders.
The set is in Smart IBL (sIBL) format, and includes a tonemapped 8,192 x 4,096-pixel panorama for the background and a 4,096 x 2,048-pixel HDR for reflections.
There are also four close-ups of the scene, for use as alternative backplates, each around 6,000 pixels in width.