Our Summit Prime 540 did not come with rear parking sensors nor was it offered by the dealer as an a option ( the van we purchased was a new one already in stock in July). Subsequently spoke to the dealer about 2 weeks ago who then quoted £300 for the sensors and which also necessitated another long trip back to the dealer for fitting. Instead found a company on line who today fitted wireless rear sensor system all in for just over £200. This was all done up my drive within about an hour. Tidy job and all working well.