I was belting along the M65 [decided to take look a the MotorPoint Car Supermarket at Burnley]
Not thinking of buying yet [though I do fancy a Mk2.5 Focus, with ESP and cruise control] possibly in a couple of years. Heard some bad feed back on the web about MP, but looking at the set up, there must have been ball park 40 Focus alone to chose from. So they must shift some motors, plus I cannot see a problem buying, if you know what your doing. Just make sure it's not an import, could be problems getting a decent choice of insurance quotes, or problems with the warranty. Check it comes with a full set of keys, only buy a car that is actually in stock at the site you visit so you know exactly what condition the interior is in. Road test it, don't pay extra for valeting or service. Valet it yourself easy enough, and get your local garage to service it, so you now it's done properly. As I reckon most dealers on selling a car just do an oil change plus a new oil filter.
Anyway back to the subject in question, with the speedometer recording 75mph, my TomTom was actually showing 71mph. I reckon the TomTom will be more accurate than the speedometer, making it out by 5.64%
Thames Valley Police: "Inaccurate speedos – the legislation referring to ten per cent accuracy went out years ago, modern cars have speedos which are allowed a tolerance that can only read fast not slow. So if your speedo says 30 you will be doing 30 or less but not faster."
Any other sat nav users noticed a discrepancy between the two?