I currently have an 00 a6 2.7t and its getting a little old and beaten up, I'm looking to upgrade to a newer audi because I love them.

I was looking at an 07 a4 2.0t, I also saw that they have a v6 a4, its an S-line so does that make it the s4? (maybe a stupid question) But I thought the s4's had a v8 twin turbo.

What should I be looking at when I am looking at an 07 a4 with around 40k miles on it (thats just an estimate).

Are the a4's fun to upgrade? Does chipping it really had around 50hp? I understand stock its about 200hp, what else is relatively easy to upgrade that'll make it more fun to drive?

Thanks guys