>What is the limiting factor with the
>1500kg (braked) weight restriction
>when towing a trailer?

The factor is the empty weight of the
towing vehicle. It's a factor of stabil
driving the car-trailer combination.
Tests by Volkswagen results, that some
Vanagons could tow up to 2000kg, which
is the limit of Germans tow bars, and,
what I guess, the structur capacity of
the frame rails. Vanagon Syncro are
allowed to tow 2500kg, if load on rear
axle exceeds 1000kg.

>The only problem I had was stopping
>( needed 30 to 50% more stopping distance )
>the rig but normal driving and acceration
>was almost un-effected.

The brakes are the limiting factor on
un-braked trailers. German requirements
are, that vehicles have to be stopped
by at least 2.5 m/s/s. Additionally there
is a limit, by law, of 750 kg for un-braked
trailers with one axle.

Official VW-Germany statements (according to
German laws) about load and towing capacity
you will find at

http://www.vw-service.de/Techdata/index.htm
select 'Anhangerbetrieb' and 'Anhangerbetrieb'
and click 'go'.
Follow the Link to 'Ratgeber'
Go the page down to Selectors, Polo is the first choice.
Find the vehicle you're searching for and click 'go'
Loading needs some time, as this are huge tables.

Regards
Helmut
'80 Vanagaudi