Hi shaun the bmw dealership were obviously going to replace everything to maintain his warranty which we have to appreciate to some extent,but lets face it in a real world i dont think any one of us in this trade would even consider that option. we have many aa and rac services bringing in wrong fuel jobs on a daily basis as we do them while the customer waits for £60 including 2 gallons of fuel and we have not had damage to any vehicle (that we are aware of) to date. as advised though you always get the customer to sign explaining that you have done the job under his instructions and can offer no gaurantees. the injectors on the hdi's function in a very similar way to the old diesel style injectors by been lifted off there seat by greater lower pressure under the needle than above so yes everything is finely machined but lets face it a minute of wrong fuel is unlikely to do long term damage..... so i hope the guy bought you a beer for saving him over £4500!!! just curious about any of his warranty aspect now that bmw are aware of his problem though.