Document everything! Every screw you buy, bulb, can of contact cement, etc. Keep track of every penny. It will be interesting to see the total (or running total) as you build.
I understand you are building the car for you, I am just playing with you with my posts lol!
Keep this in mind though, "always think resale". There's nothing wrong with building a G24, but you will in no way get back what you put in it if you decide to sell. The reason is because people who buy these cars already built are not buying them because they are a hand-built car, and definately not because they like to (or can) build. They are buying them for the "bling" value, and the perception of wealth. They want something thats gonna fool the public, and get them attention. The G24 is a terrible rendition of the Murcielago, it only fools the very naive. I still believe its a much more expensive build than the G28, since there are really no parts for them and more has to be fabricated.
Yes, people look down on the G24 because of the G28, and yes people now look down on the G28 because of the A/D kit. The A/D kit is very expensive to build though, and buying a completed car will be close to (if not over) $100K. You see completed G28's selling anywhere between $25K and $60K, which is much for affordable to the average buyer. For this reason I believe the G28 will stay the more popular build for quite some time to come. Its affordable to build, very close in accuracy, and can be sold easily for a profit if built right.
I too would like to see a G28 that has been corrected. I think it would outsell every other kit, even the A/D. When I was at Steve's (Triangle-G) house the other day and saw that G28 roadster just sitting there (as it has been for the last 3 years), I asked him if he would consider letting me have the car to rework the body. He wanted no part of it, he still is always on the lookout for Audi's lawyers.
If I can find an affordable G28 roadster body, I would buy it and change everything (and I mean EVERYTHING) that needed to be to bring the car as close to accurate as possible. I would then pull moulds of the car and put it in production as a LP670SV Roadster.
I offered steve $5K for the car as it sits, but he is still trying to get $10.5K for the body like he use to, plus another $2500 for the Fiero. I told him good luck with that, since that same body is available from CKI for $4K, and the Fiero its on is worth $1K at best.
Oh well, i'll keep looking.....