Unless the studio is modified it is pure white. The simplest and cheapest way to shoot a vehicle here is on a white, but there are various ways to produce images that do not have a white background.
In practice, studio images of cars rarely have a pure white background unless it is achieved in PhotoShop, as the white coved interior of the studio tends to reproduces as various shades of grey dependent on the lighting used. With some lighting set-ups, the background will naturally graduate from a mid-tone grey at the top through to pale grey or near white at the bottom, resulting in a comfortable and pleasing studio look. Images are frequently supplied in this simple form or with the background further shaded or bleached.
Often cars look more dramatic on darker backgrounds. Colours can appear more saturated and highlights more luminous. This can be achieved during post-production, but to achieve the very utmost in terms of colour saturation, highlight luminosity and drama, a different technique is employed. The ‘in vision’ area of the floor is painted a dark colour, dark grey or black, or the floor is covered with a dark fabric. The background is also similarly painted or draped. Post production techniques can of course be employed in addition if required or desired.
Colour tints and sky effects can be produced by lighting the background or by painting either directly onto the studio lining or on independent backdrops. Real items can of course be introduced. Provided that the proper consideration to light and reflection is given prior to shooting, digital backgrounds can be convincingly introduced during post production.
In essence, what ever can be imagined can be achieved. If you would like a vehicle to appear to be in orbit, in the Nevada Desert, a Greek island or in an entirely imaginary place, it can be done and convincingly, but please note that this can rarely be done successfully as an afterthought. Whilst in principle a background image can easily be imported during post production, it is not only the angle and perspective that must marry accurately. Due to the reflective nature of vehicles, thorough consideration needs be given to the nature of the light in the background image as well as to its colour and form. For this type of work, the background must be decided prior to shooting.
What ever you require, I am always only too happy to discuss your requirements with a view to finding economical creative solutions.