These are a couple of BMWs with prices that are still falling, so if you want to get one of these, you can consider waiting a bit longer.
E39 5 series
BMW’s fourth-generation 5 series has not only been called BMW’s best car, but also the best sedan ever. After owning a 530i for a couple of months, I can say that this isn’t unfounded. BMW undertook steps like a suspension made mostly from aluminium to build a car that is both comfortable as well as nice to drive, and achieved an excellent balance between comfort and driving pleasure. The build quality is generally better than that of the contemporary E36 and E46 3 series. The design is timeless, especially after the facelift introduced the famous angel eyes.
I’m under the impression that prices haven’t bottomed out yet, so you can probably wait a little longer. I would recommend getting a facelift model, as these look more modern and have the more powerful M54 engines. Avoid the 520i, which will probably feel sluggish being a relatively heavy car with an old-fashioned five-speed automatic transmission (few were sold with manuals). Towards the end of the production run, there were three editions that deserve special mention, as they came with lots of option: The Exclusive (geared towards comfort, with chrome and wood trim, and nappa leather), the Sport (including the M Sports package), and the Lifestyle (which is somewhere in between).
The E39 was also sold with V8 engines as 535i and 540i. If you want a daily driver, I cannot recommend them, but from a collector’s point of view, the 540i is interesting. Just keep in mind that these engines are more thirsty and less reliable than the six-cylinders. The most interesting is of course the M5, but it is considerably more expensive than other E39s.
E46 3 series
The fourth generation of the 3 series was a major success for BMW, and that’s not a surprise. Technically an evolution of the E36, it’s design was very pleasing and doesn’t look dated even today, similar to the 5 series (with which it clearly shares a common design language, just like with the E38 7 series). A noteworthy exception is the E46 compact. For reasons unknown, BMW decided to use different head- and tail lights, and the resulting look was universally disliked, which means that the compacts are the cheapest E46s.
The facelifts (sedan and touring: 2001, compact, coupé and convertible: 2003) introduced new head- and tail lights that are not really any prettier than the earlier versions, just different. More important is the difference engine-wise. In the first years of its production, the E46 continued with the E36 engines (M43, M52TÜ). These were replaced by the M54 and N42 engines in 2000 and 2001, respectively. Especially the first switch is important, as power increased from 193hp (328i) to 231hp (330i). Not surprisingly, the 330i is the most wanted and prices for these seem to be past the bottom and slowly on the rise.
The E46 is not without issues. It has the common BMW issues of suspension wear and oil use on the M54 engines, and isn’t immune to rust either. Earlier high-powered models are also prone to develop cracks at the rear subframe mounts. So make sure that this is not the case. Supply is plentiful and prices are still falling (except for the 330i), so you can afford to shop around. With prices being so low, there is really no reason to go for something less than the 325i/328i/330i. Service history and condition is more important than low mileage. Cars with M sports package are generally more desirable. Many cars have been modified, but original cars are the way to go.
E90 320si and 330i
The E90 3 series is the youngest car covered here. Prices are still falling, and younger cars are several years away from hitting the bottom, so I’d wait unless you want one as daily driver. We will have to see though whether the E90 will become a collectible classic like its predecessors. Back in 2006, Top Gear called it the ugliest car of the year, citing its bland styling. And there is some reason to this. After the somewhat controversial Bangle-era E65 7 series and E60 5 series, they probably decided to play it safe with their most important model, resulting in a car that wasn’t very exciting to look at, though some improvement was made with the facelift models. BMW also took away the driver-oriented dash.
On the other hand, the E90 is the last 3 series with naturally aspirated engines throughout the range, with the N52B30/N53B30 range being the pinnacle of many years of development. Here was a regular mass production engine with a power output of 258hp (N52) or 272hp (N53), bringing the power close to the 286hp of the E36 M3’s S50B30 engine. This makes the E90 330i a seriously quick car. The early 325i with the M52B25 engine dominates the very popular V4 class of the Nürburgring-based VLN race series, proving that this model handles well, too. If you want even more power, there’s the turbocharged 335i, but I’d personally prefer a naturally aspirated engine.
Typical for modern cars, the E90 is quite complex. The engines feature Valvetronic and later (N53) also direct fuel injection. The navigation/media system is iDrive-based. This makes repairs and modifications more difficult. This is something to keep in mind.
A special case is the 320si. It is BMW’s last homologation special. With the E46, BMW was forced to use a six-cylinder engine for its touring cars, which was less powerful than e.g. the Alfa Romeo engines. Due to the popularity of touring car racing at the time and a new World Touring Car Championship, BMW decided to bite the bullet and build 2,600 homologation cars as 320si. The engine, called N45B20S, was essentially a non-Valvetronic version of the N42 engine. It was hand-built and modified for racing use, with the most visible cue being a carbon valve cover. Unlike other homologation specials, the 320si has so far failed to attract much attention, and prices are low and still falling. This has two reasons:
- The 320si has a two-litre engine with 173hp, compared to the 258hp of the 330i. Yes, it handles better due to its lighter weight, but from a performance standpoint there’s little reason to choose the 320si.
- The engine has proven to be unreliable, mostly due to soft aluminium cylinder liners. It works perfectly fine as racing engine that is overhauled every couple of races, but is not always able to cope with daily driving.
Nevertheless, I expect that, at some point in the future, these homologation specials will appreciate in value. This means that it might be worth buying one by the time the prices reach the bottom. If you do so, make sure that the engine is in good condition (preferably already overhauled, possibly with steel cylinder liners that should cure the liner issues) and that it is all-original, including the original styling 216 wheels that the car came with.