Is it true that cars with a turbo require a more expensive oil at servicing?

I've booked my Vauxhall Mokka SE 1.4 turbo in for a service. They tell me I need to pay £20 extra for special oil as my car is a turbo. Is this correct?

When should a car's oil level be checked?

When should the oil level in a car be checked? Is it when the car is cold, warm or hot?

My car is 15 years old, do I need to replace the seat belt tensioners and airbag modules?

In the service book for my 2002 Skoda Fabia, it says that at 15 years old the seatbelt tensioners and airbag modules need to be replaced. What if I don't have the work done? Also, it's done 67,000 miles...

Volkswagen Passat (2001 - 2005)

A better drive and better equipped than the previous Passat. Comfortable and has more status than, say, a Ford Mondeo.