Problem is that all the work you did is maintenance ... should add to the 'reconditioning' amount, but not by very much unless it was done in the last 3 or 6 months.
If you took your can in to get work done, and especially if you have a good rapport with the guys who did the work, tell him to go chat with them. Bring along receipts for your sound system too.
Go on the web and find CSVT's for sale, and print them off as proof of your required costs to replace the vehicle.
If you can think of anything ... research it on the web and print it off, add all your receipts for any amount of time.
When this happened to me I had every single invoice for the three years I had the car, glowing reports from the service guys who worked on the car, printed adverts from autotrader for CSVT's (even though mine was a Mystique) book value for Canadian values, book value for US values, and telephone numbers/written quotes from people who had actually driven my car. Now I lucked out a little as the appraiser went to school with one of the service guys ... and the service dept. all love me too

In the end I managed to get $7,000 CDN back, which was upped from about $5,500. The appraiser basically told me I could more or less have the going rate for an SVT as in his opinion I had 'turned it into an SVT'.
Bare in mind ... once your company tenders an offer to you, benefits stop, things like car rental coverage although I managed to get an extra week coverage.
Make sure you buy the car back if you can ... stripping it will seriously help recoup the costs, and especially all the new parts. Tell your company this NOW ... mine was sold from under my nose as soon as the tender went in.