What car should my dad get? Read the description....?

[Cal]

My dad's lease on his E350 is up this August, and since I know alot about BMWs, Audis, so he consulted me to find his next car. He had an 2003 E320 for five years, then get a E350 in 2008, and he hates it becuase he has technically had the same car for seven years. He only got a 27 month lease because he wanted to get the new E'class, and even though it has changed alot, he doesnt want another Mercedes, and he feels like he doesn't matter to the Mercedes dealer. He got a 27 month lease, and 8,709 miles on his engine, the tires had like caved in or something. He took it to the dealer when he first noticed it, and they said the 4-Matic beats up the tires, and that he's have to pay for new tires. He did get new ones after another like 2,000 miles, a new, nice set of Perrellis, that he paid for. Anyway, he has always had an interest in the 2002-2008 BMW 750li, and he was amazed at the price for the used ones. I also suggusted the Audi A8, but he was a bit concerned about only a 4.2 V8 engine, but the BMW is a, what, 4.4 V8, or a 4.8 V8? IDK one of the two. He once owned a 1978 Porcshe the absolutly loved, but he never drove it, and caused too many problems, so he sold it. I'm pissed at him for that! So, any suggestions? He wants a fancy car, like an Audi, or something, and something big, and needs to be a sedan, with a big fast engine. Price range, anywhere up to about $58,000.