Marshalls Cambridge 20K
Little expensive maybe, but did engine flush and didn't mess up the tyre pressures this time.  
 
Only took 90 mins while I waited, offered to wash the car but I declined, supplied brake pads for £114.
Coffee and TV while waiting (not that daytime tv is a good thing  

 )
Overall  

 maybe a little expensive at £200 but not sure what a 20K service should cost.
SNIP
On my last car (Toledo 1.8 20V) took 4 visits to sort out why the fuel gauge failed to register an empty tank ie no warning light or bell onlty worked some times usually with only about 6 miles left in tank 
  
 
in the end all they had to do was do a factory reset on cpu 
 
Last 
problem was at 60k service (at independant garage) found marshalls had fitted aircon pump incorrectly causing punp caseing to fracture and bolt to shear off 
  
  so returned car to marshalls as pump only 4 months old(impelar had disintegrated)and was replaced under warenty, took them 4 days to repair,
on servicing usually fine allways did work required and either coutesy cars or collection as required.. 
 
John