Hello, I am new to the audi world and the a8 especially. Are there any options for upgrading power and handling in the d2 A8s?

I have been trolling the net and have almost no options for sale or otherwise aside from some brake and suspension packages.

if you can not tune up or modify the current 4.2 v8 are there options for swapping to a newer more tuneable version of the motor? are the motor mounts even the same? has anyone ever attempted this? Would I do better just tearing down, rebuilding with forged internals and boosting it?

Again I have seen no tuning options, has anyone ever put a piggy back system on their a8 or gone stand alone for engine management?

Last but not least has anyone here ever megasquirted their audi?