"X models account for as much as 30 or 40 per cent of total sales in some months. The general trend across the market tends to be that compact SUV sales are really surging."
The X4 will join an ever-increasing number of niche-filling products from the Munich marque, which include the X6 and 5-Series GT. A 6-Series Gran Coupe is due later this year, plus numerous variants based on the new 1-Series and 3-Series are in the pipeline.
Scott could not confirm rumours that a high-performance X4M was planned, although he says it is conceivable that a "range-topping version that the M division has had a hand in" could emerge under BMW's M Performance Automobiles banner.
M Performance Automobiles, the first of which will be an X6 expected to feature a triple-turbo diesel engine, will be hotted-up versions of BMW's existing vehicles, but will stop short of being full-blown M cars.
BMW made the X4 announcement as it celebrated the two-millionth vehicle to be produced at Spartanburg since the first car, an E36 318i sedan, rolled off the line in September 1994.
The Bavarian brand also announced a US$900 million ($1.1 billion) investment in the facility by 2014, which will expand annual capacity to 350,000 units and make way for the new X4.
This follows a 73 per cent production increase to a record 276,065 vehicles last year, largely due to demand for the second-generation X3, which went to Spartanburg in 2010 after BMW decided to stop producing the model in Europe.