If I were you I would get more quotes it seems a little high to me last year I had a detachable towbar fitted to my 2013 Alfa Romeo and I think it was only about £260 s my car is not as popular as yours you would think mine would be a lot higher. One advantage of dedicated wiring is if you needed warranty work done but a 2009 car wouldn't be covered anyway, the other reason is reverse sensors maynot work properly
------------- its our imperfections that makes us perfect
Mostly an urban myth re warranty work. I have a 2012 vehicle with a five year warranty and needed about £7K worth of work, and at no point was I asked if I had dedicated electrics.
I never have had dedicated electrics and never had a problem.
------------- XVI yes?
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
dedicated electrics basically just means instead of cutting into the existing wiring at the back end of the car (lights etc) they run new wires from the engine bay.
Ive never known anyone to have that done.
Also, as someone else has said, that sounds really expensive for a tow bar, our 2010 CRV bar only cost £250 fitted
------------- If it wasnt for bad luck, i'd have no luck at all
Dedicated wiring means you connect up to the cars Canbus system, not just wire to the front end.
With dedicated electrics on my Seat the bulb failure warning system covers the trailer lights and if one of the bulbs does fail the Canbus system uses one of the remaining bulbs on the trailer instead. IE if an indicator bulb fails it flashes the side light bulb instead.
It also cuts off the reverse sensors when the trailer is fitted. Also supposed to change the settings on the Electronic Stbility Control but I have no way of knowing whether it does or not.
if you look on various car forums you so see that owners have had lots of problems with newer trailers/caravans that have led rear lights when using By Pass wiring.
Having said all that the price does seem high. Already had a towbar fitted but 13 pin socket with dedicated wiring and recoding of the Canbus system cost me £145
Dedicated looms usually £100 odd. Towbar around £100. Add a couple of hours labour & cost should be less than £400. As suggested, get some more quotes. I would go for dedicated loom if you can.
New car warranty is only affected if any problems caused by non approved towbar need main dealer to sort out. Obviously faults directly caused by towbar fitting will not be covered.
I think ours was about £400 for a detachable tow bar and dual electrics (by pass relay for fridge etc) and was wired to the front. I was offered dedicated but it was a lot more and I was told I would still have to take it to VW to get the software changed to take advantage of it (and all it seemed to offer was muting of parking sensors, automatically turn off stop/start - VW say you need to do this when towing, but never worked out why, and puts a picture of trailer on the car multimedia display when selecting reverser, in case you had forgotten (useful :-) ) - so I didn't bother
If your VW Golf has Stop/Start then you need dedicated electrics, reason for this is that the dedicated electrics will disable the stop/start function, when a trailer is being towed, otherwise you have to rember to do that manually every time you get in the car when towing.
There are probably also other functions, that are worked out by the engine management system.
On the VW Golf I drive, 2015 model, the radio display shows an image of a trailer, and as already mentioned the trailer lights are included in fault reports via the OSD, and of course the car alarm system is integrated with the trailer electrical connection.
Towbar Swan Neck c/w Single 13 pin fully wired socket came to £470 back in May 2015.
Any tow bar fitting firm worth there salt, will have the software and kit to code the dedicated electrics to the car.
My VW handbook says the same thing about stop/start when towing (2011 Tiguan). Talks about "could cause damage" But I could not figure out why (and sometime forget to turn it off). Do you know why it is?
My only guess was that engine power was needed to manage the auto-hold brake, and if the car does not know about the extra load on the tow bar, it might think it can hold the brakes on (on an uphill slope) with the engine off, but in reality it can't, and might start rolling back?
Dedicated electrics also allow the trailer fog lights to be on without the car ones being on (and reflecting back off the trailer) - although my tow bar fitting put a clever box in which also manages this.