First off, for modability you don't want a 2011 for couple reasons:
1. They are much heavier. My 2010 is 3700 - 3800lbs. The 2011+ is based off the 7 series and is 4300lbs. That's at least a 500lb difference.
2. They handle appreciably worse than the previous generation 5 series.
3. And this is the biggie: they have a different engine. The 2011+ cars get the N55 which switched from twin turbos to a twin scroll single turbo. A tune doesn't get you nearly as far on these cars as it does on the previous gens which in real world terms means that even with a tune you're likely only going to be as fast as my car was stock since you're starting off with a 0-60 time that's regularly 1/2 second slower than the E60 5.
The only thing the newer 5 has over the older 5 is a nicer looking interior. My 2010 has all the same features but I'll be the first to admit that BMW really spruced it up and stepped up their game with the 2011's.
Couple random things:
- It's a misconception that the 5 is appreciably slower than the 3. The two generally are within 100lbs of each other. It's just that people that mod and want to make the cars go fast generally buy the 3 because it's perceived as being the more sporty of the two cars. So for every 20 335s you see that are modded you might see 1 535 and the 535 guys tend not to mod as extensively as the 335 guys. Mod for mod though, they're generally just as fast.
- Skip xDrive unless you absolutely need it (you don't). I rolled on 285mm summer rubber in the back and the only days I couldn't take the car out in Chicago were the days where it was snowing hard enough that the streets were covered and again, we're talking summer performance tires. Put all seasons or winters on it for the winter and you're golden. Remember, AWD with normal tires generally isn't as good as a similar car with winter tires on it. People see AWD and assume that the vehicle is going to be a monster in the snow and are generally disappointed when they realize they still need to run better tires.
- The real reason to avoid xDrive is because the suspension blows. It's soft, it wallows and even if you get the M-Sport package it drives like a standard suspension 5 series which is to say: soft. You're neutering the car. Plus the non-Xdrive sport cars get the larger 550 brakes.
- Get one with the sport auto transmission. It adds paddle shifters but more importantly it adds sport mode which results in shifts so blindingly quick you'll wonder if it's not a dual clutch transmission. Combine that with the fact that the car will let you hold each gear to redline and blips the throttle on downshifts and you have a car that's as near to a manual transmission as you can get while still being able to drive docile and smooth in automatic mode.
- Go with the e60. It is by far the better driving car, a more engaging car, a lighter car and a faster car with a better engine.
Not to mention you can get standard sport package E60's in the low 20's with reasonable mileage. They might be lighter on the options and they won't have the M-Sport package but they'll be every bit as capable… OR…
You can buy my 2010. $30,000 - 38,000 miles, Cold weather (heated steering wheel, heated seats), Nav, M-Sport, real M6 rims, Sport Auto Transmission (nearly impossible to find), comfort access (touch a door handle and the car unlocks), Harmon Kardon L7 Stereo. The only options it doesn't have are night vision, heads up and cooled seats (which are nearly impossible to find in anything but an M5). To find a 535 optioned like this is really hard since the 535's are typically considered a mid-level 5 series and are thus generally lighter optioned than say a 550.
It's been tuned and is running E85 about 50% of the time. No issues other than an over boost problem I was having chronically which ended up being ignition blowout and was fixed with new spark plugs which do need to be changed more often when you're tuned. It's been converted to a quad exhaust with a carbon fiber diffuser, has HID halos, 20% tints, and tinted tail lights which are a film that can be removed in 10 seconds if that's not your thing. I have all the stock parts as well.
Just got a clean bill of health from BMW last week. I love it, I don't need to sell it but if someone were to take it off my hands it would open other doors for me…