I think they may have engine oil confused with automatic transmission and dipstick with drain plug.
Many modern European cars do not have a auto transmission dipstick. To check the ATF you use the drain plug. The drain plug has a small drain plug in the center of a large one. The small plug has a stand pipe attached to it. The top is the pipe is the correct fluid level for a set temp of the fluid.
So the procedure is to slightly overfill the trans, start the engine and warm up until the trans fluid temp on the scan tool shows the correct temp (50C for Volvos, I don’t know about the others), then raise the car, pull the small plug and allow the excess to drain.
I know of no European car with no engine drain plug.
How do you add transmission fluid to one of these if there’s no dipstick tube to pour it into?
GM had no transmission dipstick on the Malibu back about 8 years ago. There was no obvious way to check or add transmission fluid and I’m pretty sure there was no drain plug on the pan either.
There is a fill port, just no dipstick to go with it.
We have a Smart fortwo Diesel. They do not come with drain plug in the oil sump.
The car was used but had the balance of its factory warranty. The original owner had installed a drain plug and the first time we took the car for warranty service, the dealer (Mercedes Benz) informed us that the warranty was void because of the modification.
It turned out that any warranty service had to be pre-approved at the national level. We were never refused, but it was a bit worrisome…
I would think that most service shops would like the vacuum system. In doesn’t have to tie up a hoist and the tech can be off generating $$ while the goo gets sucked out.
I can buy an oil extractor for about $50. but I will make make one for the priceof the plastic tubing.
they cannot unilaterally void the warranty for something like that. They can deny a specific warranty claim if they can show that a part or modification is the cause of the failure.
How will you get the oil to come out? You need suction.
You’re forgetting about the oil filter. I haven’t seen too many cars where you can access the filter from the top.
It’s pointless to change the oil without the filter being changed although I remember some quick oil change places being accused of doing that.
They definitely said it was the engine oil sump that had no drain plug, they spoke in unkind terms of our bosses new Passat, saying that it’s undertray was a bitch to remove, and once it was off, no sign of a sump plug. They ended up phoning a man they know at the dealers, and were told you have to suck it out, and that it’s increasingly common, especially on German cars.
These are experienced mechanics, who work on cars, vans, tractors and lorries every day, I trust them to identify the correct sump to be drained.
Please correct me if I am wrong but your use of the word “lorries” leads me to believe that you live in Europe. I do not know about the cars there but as far as I know every Mercedes, Audi, VW, BMW I have performed an oil change on, in the US, has a drain plug on it. Although I do not see many of those model vehicles I do get a “non-Toyota” almost every day since the dealership I work for has a very large used car department.
They don’t sell diesel smarts here in the US but I can tell you for a fact the gas engine versions sold in the US have a drain plug. I’ve seen them. (had a couple of those POS on the used car line)
Ditto for C and E class Mercedes. Drain plugs.
The 98-06 SmartCar 450 had no drain plug. Not counting 1000 special imports on 06, SmartCars in the US are 08 and up 451s with drain plugs.
I have a vacuum pump, a 5 litre jug and the appropriate plumbing.
I see. That’s cheating. 
At least for BMW, he has it entirely backwards.
On most (all?) new BMWs, including my friend’s new 335i, there is no dipstick. An electronic sensor measures the level. The only way to change the oil is via the drain plug.
I doubt this was done to make maintenance harder. The oil filter is still right at the top of the engine and can be changed about as easily as a windshield wiper. It’s more likely that it was a cost savings and packaging decision (engine bays in newer BMW’s with big engines are crammed full of stuff, and the dipstick tube and associated mounting hardware takes up a non-trivial amount of space).
I hear on the Smart Cars with no drain plug you can just take off the oil cap and turn them upside down to drain the oil. 
I have a hand actuated vacuum pump. Bought it because the race car has rather expensive coolant and I wanted to keep it. More importantly, it’s a marine tool usually used to suck the oil out of inboard motors. They do it a lot that way because it’s physically impossible to get a pan under the drain in the bottom of a boat.