So can we assume they already had the car ? was it one of CJ's or had they got permission to move EW's ? Google maps from 2010 appears to show a light blue Fiat Panda 4 X 4 on the drive.
Perhaps he had a car but by the time of his arrest he no longer had it...he'd perhaps reported it stolen, hid it away, sold it..whatever. If you had killed someone and had them in the car would you really want to hang on to that car? I'd be desperate to get rid of it or distance myself from it, me. Would you trust that just a good vacuuming or valeting would dispense with any signs? I wouldn't, and the fact that they had their cars valeted soon afterwards has been used against quite a few convicted murderers.
VT was living at Aberdeen Road, he'd also been up to Cambridge afterwards. I don't think we know yet for certain whether he flew, got the train or even took a car to Holland do we? Compared to press reports about CS there's been a marked lack of gossiping neighbours where VT is concerned. If, before his arrest, he did happen to dispose of his car, his close family and friends are hardly going to announce that fact are they...because he was away from Canynge Road over Christmas neighbours there wouldn't know if he still had a car or he didn't.
He could even have hired a car for a day that weekend to move the body. The police could possibly have taken a car he'd driven over that period. If they didn't take it from Canynge or Aberdeen Road the press wouldn't be around to know or to witness it actually being taken then would they? If they later found out and he'd been charged by then they wouldn't be able to report it by that point.