Most of the time a standard service is simply just a change of oil and filter.
Personally, I have my car serviced at Hyundai. Though, I know them and the guys that work there own Subaru's themselves.
I don't believe there is a problem with an apprentice working on the car, It's not rocket science.
If anyone managed to catch 'The Checkout' on abc the other night. http://www.abc.net.a...isodes/ep01.htm
It discusses about how manufacturers such as Holden, Subaru, Mazda etc. In this example Mazda say "It must be serviced to Mazda specifications and standards every six months" and "Failure to maintain your Mazda in accordance with the requirements may void your New Vehicle Warranty"
When in fact, this is breaching Australian law.
I recommend you watch the video I've linked. (26 mins in)
In summary, Theres no need to have your car serviced at Subaru
