M.O.T Advice

After 45+ years of caravanning and now on my own I decided to buy a 2017 Auto Sleeper Symbol about 9 months ago and have been extremely grateful for the help and assistance offered by members of this group.  After a few warranty issues, which were sorted, I set out to book it in for it's third ( 6year) service and M.O.T., at a local dealers, and discovered some of the trials and tribulations of owning a campervan.  My Symbol is actually based on the Fiat Ducato chassis as it has a Comfortmatic gearbox.

I have been given a quote for the work which is quite high as Fiat recommend brake fluid replacement and service kit, which contains cam belt and water pump, every 6 years or 120,000 miles which ever comes sooner.  In fact the quote is split into 2 with genuine Fiat parts for the service kit compared with non genuine parts and a significant saving.  Has anybody got any information about using non genuine parts for service kits, good or bad ?

My Symbol has a maximum weight of 3,300kgs and has been booked in for a class 4 M.O.T.  I assumed that class 4 was for vehicles up to 3,000 Kgs and vehicles from 3,000 Kgs to 3,500Kgs were class 7.  Am I missing something ?  Bill

If using none genuine service parts for the cam belt I would advise only to use a Gates manufactured item. They do supply a large proportion of the manufacturing industry but probably still cheaper to buy direct, I would ask the question. If the belt fails the consequences are very expensive.