And if your service book does not have a main dealer stamp, it will affect the resale price.
HTH
Sorry, I totally disagree.
To date, between my wife and I, our GTI is our 33rd car in 23yrs!!!
I have never, ever been asked if my FSH is at a main dealer. Yes, Ive been asked if the car Im trading in has a FSH, but never where it was done.
Then I think you are the the exception rather than the norm. EVERY franchised dealer, and most independent car sales outfits which I have ever traded a car into (or even just made preliminary enquiries) has ALWAYS asked if it not only has a FSH, but also if it has a main dealer FSH. And these are on virtually all kinds of make of car, even Fords, Vauxhalls, VWs, Renaults, Jap, Korean shyte - or whatever (the french Jap & korean crap were my customers!). And this is based from over 30 years experience in the motor trade.
TBH, in my experience, dealers pay very little attention to a car having a FSH. They certainly wont give you anymore money if it has, although they may knock a little bit off if there isnt one.
Well you have just completely contradicted yourself. Quote:
'they won't give you anymore money if it has (a FSH), although they may knock a little bit off if there isnt one'. So they WILL give you less money without a main dealer FSH!

The only exceptions to this rule are for high end cars like Jags, Mercs, etc. FSH is essential due to the running costs of these cars. Also, they will usually have a FSH as they are normally company cars for the first 3 yrs.
Nope. In my very valuable and direct experience, even the mainstream family marques will all be devalued if they do NOT have a main dealer FSH.
And your 'company car' issue is also misleading. Because how many 'specialist' high performance cars, such as Audi S4/RS4s, Audi R8s, Porsche 911s, BMW M3s, Mercedes AMG models are 'company cars'? Hardly any - the vast majority of these cars are bought by private individuals who are 'enthusiasts' - and certainly know the importance of not only protecting the official manufacturers warranty - but equally as important, protecting any 'goodwill' once the warranty has expired. In fact, this post-warranty goodwill also applies to the likes of Ford and Vauxhall. Have a full main dealer warranty, and they will look after you long after the warranty has expired. No main dealer service, then you will have to fight to get the absolute bare minimum warranty - and can completely kiss goodby to any 'goodwill'.
Just really wanted to say that in 23yrs of car ownership where I used to meticulously maintain my cars at the main dealers, I have never felt that this added to my cars value at trade in time. I now get my son to service my cars as hes a fully qualified mechanic and can stamp my FSH with the Ford dealers stamp. - Its a proper full service with genuine VW parts. However, I know its done right and with a bit of car and attention.
I do not dispute that at all. I fully accept that in many cases, a dedicated independent specialist will usually offer a higher quality level of service than the main dealer. However, without being disrepectful to your son - unless he has gained any independent automotive qualifications outside what the manufacturers offer - then he ain't really any better than a VW main dealer mech/tech (and just to emphasise - I am NOT doubting the 'care and attention' which your son can offer

).
The ONLY benefit IMHO of using the main dealer is that they can apply any software updates/recalls.
Using the main dealer offers far more benefits than that - but yes, the software updates are very valid. However, some of the dedicated marque-specialist independents can now offer this facility.
As for official recalls - then it doesn't matter if you use the main dealer or not. Because these are raised via the DVLA to the registered keeper.

Again, according to my son, software updates are never done UNLESS the customer reports a fault/problem.
Rubbish. All main dealers, as a matter of routine, should ALWAYS check for the latest software updates - irrespective of weather the customer reports any faults or not. OK, there may be the odd occasional main dealer who doesn't do this - but they are the exception rather than the norm.