Hi I'm the driver of the CLS and was told by my friend from the forum that there's this huge thread about my car, an M5 and Patterson Road. So I went to take a look and was quite surprised how lively this forum is. Couldn't resist so I joined to post as well.
Harry, first of all I must say that your M5 was &%@$-ing fast and one of the fastest things I've seen. Its in fact very close to an F430 (The F430 I encountered seemed just slightly quicker ). The M5 is definitely faster than an 05 Gallardo and probably around the same as an 06 Gallardo/Spyder.
Actually my first choice was an M5 but I thought it was abit overpriced here (relatively speaking when comparing both cars' prices in Europe). I have read alot about the awesome straight line performance of a stock M5, esp at high speeds due to the 7spd gearing, but figured that those kinds of speeds will hardly be reached here in S'pore. Still the M5 has the advantage of being NA as its performance won't be affected so much by the heat/humidity of Singapore. I think with just a closer ratio differential mod, ECU, exhaust and some lightweight pulleys, your car will really be flying and sounding awesome as well! Don't need to spend alot of money. I spent around 20k on my car with around half that amount on exhaust alone. Oh, and my car has dynoed less than 600bhp, though I wish it really had 600+ or 700+bhp as mentioned by some of you guys!
On a side note, I know that for some countries they put these very restrictive charcoal filter things in the M5's airbox to meet emission requirements and just by removing them you get more power straight away. You should look into that if not already done so mate