I done the stelvio and ring in june this year. Was one of the best things ive done. Already booked for the ring and black forest next june. 
  
our trip went like 
  
day 1 folkestone to calais, through belgium and Luxembourg to strasbourg. 
  
day 2 strasbourg through to Switzerland then italy stelvio 
  
day 3 stelvio back through Switzerland onto stuttgart 
  
day 4 stuttgart to the ring 
  
day 5 ring back through belgium then calais and home 
  
next years will be 
  
day 1 folkestone to calais straight to the ring 
  
day 2 ring to baden baden black forest 
  
day 3 black forest to Munich 
  
day 4 munich to bmw and audi factory 
  
day 5 munich to ring 
  
day 6 enjoy day at ring 
  
day 7 another ring day then calais and home