This next car checks the all boxes; manual gearbox, check. Wagon, check. Inline-6, check. Rear-wheel-drive, check. Headliner...errr...that's missing....and the miles are high, so you will need to do some tidying before you let the wife drive it...but manual transmission rear-drive wagons don't grow on trees. Find this 1992 BMW 525iT offered for $6500 in Long Beach, CA via craigslist. Tip from Rock On!
The Christian feast of the Epiphany is celebrated on January 6th, (the word Epiphany comes from the ancient Greek work Τheophaneia meaning "vision of God") and is a commemoration of the three Magi visiting the infant Jesus. Around here we celebrate the Epiphany by posting 3 cars, one for each of the magi, next up is Balthasar who delivered a gift of Frankincense, which is a kind of resin that is burned and represents divinity. I couldn't find a car that burned copious amounts of oil or coolant, so instead I've got a BMW wagon equipped with angel eyes or halos...which is as holy as I could find for a BMW. Find this 2001 BMW 525iT offered for $6000 in Los Angeles, CA via craigslist. Tip from FuelTruck.
The BMW E34 5-series was a large luxury family car from BMW, available as a sedan or wagon (estate). We don't see the wagon versions very often on the road anymore, but they offer a surprising amount of room for the kids/gear/junk while maintaining the classic BMW luxury, handling and performance. Regrettably, for the US market BMW felt it only needed an inline-6 in the wagon when equipped with a manual gearbox, or a small V8 when equipped with a slushbox, but some visionary lunatic decided the E34 needed a V12 6-speed. Find this 1993 BMW 550i V12 Wagon E34 offered for $18,000 in East Hampton, CT via craigslist. Tip from Bill.
The E34 generation BMW 5-series was available as a sedan in 525i, 530i, 540i, and M5 versions...but if you wanted the wagon you had to settle for 525i/530i versions only in North America...and to make matters worse, you couldn't even get a manual gearbox, unless you get a modified one like this next feature. Find this 1993 BMW 525i Wagon 5-Speed offered for $5000 in Denver, CO via craigslist. Tip from Rock On!
Long after luxury brands like Mercedes-Benz, Cadillac, and Lincoln had abandoned the manual gearbox in favor of torque converters or flappy paddles, there was a little company from Bavaria that continued to put clutches in their executive class cruisers. This is great because it means that 10-15 years after they leave the showrooms, these executive class things become well priced and are still fun to drive. Find this 2001 BMW 525i offered for $3,650 in Los Angeles, CA via craigslist. Tip from FuelTruck.
The E34 generation BMW 5-series replaced in the E28 for the 1988 model year and featured (for the North American market) a variety of inline-6 engines for your motoring needs. A V8 version was offered starting in 1993, but the muted howl of the inline-6 is more than adequate for your driving needs...especially when mated to a manual gearbox. Find this 1992 BMW 525i Wagon with M54 swap offered for $3,200 in the SF Valley, CA via craigslist.
The clever German title above translates to "clean bar of soap." I'd also like to remind readers that Sauber is the Formula 1 team that BMW owned from 2005 through 2009. They had mixed successes, but it was the debut team for 4-time world champion Sebastian Vettel - where he started his F1 career as a test driver. It seems like Vettel is an old master now, but I was present to see his first F1 race ever, at Indianapolis in 2007 (just yesterday, really). I find it fitting that this wagon not only resembles the proverbial bar of soap (and matches the white BMW Sauber F1 livery) but that it is a clean slate for modification, from mild to wild. Find this 1995 BMW 525iT E34 wagon for sale in Portland, Oregon for $3,500 via craigslist.
This next car comes as a tip from J Jefferson who writes: $7K
US for a BMW with 25k miles (40,000 km) seems cheap, but who know what
gremlins could be lurking in any car this old. Funny little mast on the
right front bumper too… does it come from an embassy fleet? This is
near Canada’s capital, home to all sorts of foreign nationals, so a
plausible theory. Nothing prosaic on the site to help figure out why
this beast has only been driven 1,000 miles per year. If it weren’t an
automatic, this would already be in my driveway….( that’s what we all
say, isn’t it). Find this 1989 BMW 525i Auto offered for $8,988 CAD ($7,200 USD) on motorhouse.ca, located in Ontario, Canada.
The E34 generation BMW M5 is an awesome vehicle. So awesome, that DT's CFlo drives his regularly (especially when it rains in SoCal) and our 2013 E34 M5 market watch story (syndicated here on Jalopnik) is the 6th result from the top when you search google for E34 BMW M5. However, if you want the M5 experience but don't want the M5's heavy return throttle spring, ocean liner scale fuel bills, needy maintenance schedule, balky un-rebuildable gearbox, and potentially bankrupting catastrophic S38 repair bills...perhaps you should consider this instead. It is a 1995 BMW 5-Series that has been given the S52 inline-6 from a 1999 BMW M3, find it here on eBay
currently bidding for $7,977 reserve-not-met with less than 1 day to go, located in Pennsylvania. 
The E34 generation BMW 5-series was sold from 1988 to 1996 in the North American market and solidified BMW's reputation as a builder of sport-luxury sedans for the quasi-wealthy. The 5-series was not the ride of Rockefellers or rock stars, but it was the choice for doctors, lawyers, middle managers and folks who wanted a nice sedan with a touch of speed. Today the E34 is cheap enough to be the choice of window clerks at your local burger barn, but that shouldn't dissuade you from experiencing one of Bavaria's better built bombers. Find this 1993 BMW 525I E34 Touring with E36 M3 powerplant offered for $4,500 via craigslist. 
The BMW E34 5-series was a large luxury family car from BMW, available as a sedan or wagon (estate). We don't see the wagon versions very often on the road anymore, but they offer a surprising amount of room for the kids/gear/junk while maintaining the classic BMW luxury, handling and performance. This 1992 BMW 525i E34 wagon is for sale in Feasterville-Trevose, PA offered for $7,950 or-best-offer via ebay. Big thanks to tip from Oldsmobuick.