Ahahaha, you think he doesn't know it's the "big 4 year service next"?. If some mechanic who barely knows how to drive a car offered me a free "big" service I'd be running for the hills.
Chances are he will give you a "free" service but because of a couple of bolts and jubilee clips he accidentally loosens, you'll be crawling back a month later to put £800 in his back pocket.
The old "free service" joke is the worst joke you'll ever hear.
Garage is proper Toyota dealership so I trust them to do the job correct, plus the service jobs are all recorded online now.
How old are your tires, they look to be weathering really badly with all the cracks in the rubber.
Tyres are 17k and 3 years old.

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