Yes, the 240`s does have the headlight wipers at least my fathers 88 240 GL and I think all the way to 93 model.But if I remember it right the wipers is longer on 240`s then on my 740.The headlights are not the same on 240`s and 740`s but You know that already.But thats not a problem it must be the same thing to hook up a wiper on a 240 as on a 740.The rest of the things behind the headlights, motors and the cables the fluid runs through must be same princip.If You have a 90 You dont have those two rectangulars lights in one headlight (USA-lights as we say in Sweden, very popular that young people put them on instead of our one light headlight system, they think the car look better with them) I suppose, strange that You dont have headlight wipers in such case.I dont recognice those three raised bumps as You mention, but I have seen some pictures on 90`s and later USA-models of 240`s and the headlights on them seems to be much the same as ours in Sweden and if so You should be able to put wipers on, but I can have wrong there.You dont have a Volvo shop around there who can help You and where You can buy the things You need to install it.

Mikael