The problems

Having spoken to Locauto's customer service (0039.02.43020342), I ended up with two:
 
1. Locauto weren't going to refund the recovery cost (100 euro / £87.41)
2. Locauto were going to charge me 232.73 euro (£204.85) for repairs to the clutch
 
This kicked off a long communication with Nadia at "customer services".  If you want to see the emails, go to here.
 
Did I get anywhere with these people?  Of course not.  Having dug out receipts, scanned them, faxed them to Locauto, sent telephone conversation records and inconvienced my Italian-speaking friend, and reported the story about the mechanic and the oil, i ended up with nothing.
 
Well, almost nothing.  I did get the satisfaction of an admission that whilst Locauto understood that I had no choice as to whether to use the SALT tow truck, they were not going to refund my money because I didn't tell them that this was what I was going to do.  I remain confused as to why Locauto knowing this would have made any difference given we were given no choice by the SALT patrol.  Bizzare.  And expensive.

Maybe i should have spent a bit more time researching Locauto before using the service.
 
Oh, and i forgot to mention - the fuel gauge on the replacement car didn't work properly.  So I ended up piling 40 euro into an unattended self-service petrol pump to add 15 euro of fuel.