According to the guy who built the car, It would be the BBM stage 4 upgrade kit, plus all the engine work (ported polished head, intake manifold, bored out engine to a 2.0l, etc). I was told that it was making over 200hp.
The guy who built the car is Speedig60, here is a link but if you search his username you will see all the work that was done to this car. Since I have had it, I installed the 6speed transmission. It definately needs a standalone system.
99 golf Wolfsburg edition. 5 speed. About 130k miles. Garage kept. Super clean and I've kept it mostly OEM no major or permanent mods. 1st place in class at VolksFest last month. Mods: coilovers,catback exhaust, intake, jetta front end, sound system, battery relocate, and some minor engine deletes.
I have full maintenance history and Ive kept every part and bolt that I've removed. Only needs an alignment at the moment
The book value is probably anywhere from $2,000-$2,500. I dont count mods into the value with trades or sales. I know that your cars book value is probably $4,000-$5,000. Really depends on if you want a more "family" car i guess. I have a trade pending with another guy. Its an un-molested 1990 G60 in better condition. He is asking $5k and wants to trade straight up. But thats only because he has a kid now and needs a 4 door so it makes sense for him.