I reckon with super grippy tyres, perfect tarmac and good shifts you could possibly get 7.8 but really your not going to get under 8 secs on the road, on the strip maybe where they spray it with glue.
Timing video is not the most accurate way anyway as the speedo needle doesn't even start to move until you're already rolling. The only way to do it properly is with timing gear or on a drag strip that records 0-60.
I'm not trying to pee on your parade but I've owned and driven a huge number of cars and I know for a fact a bog standard MKIII 16v is not capable of sub 8 sec sprints to 60 without a fair bit of tuning and perfect shifting.
nick