probably wont be far off. A quick google search doesn't yield an answer so you might want to ask in the K12 secion if somebody can measure their sill to get an idea!
and NPOC - that's a blast from the past! I do occasionally check the MOT status of the red Primera (its still on the road - MOT was done a few weeks back, 25 years old now so somebody is looking after it!!) and nearly bought it back a few years ago (well, I nearly did until the wife said no - so I rebelled and bought a Renault Megane RS 300!)