Could be anything. someone who calls a 5 door a 343, doesnt even has a clue at all. Could be a 345, or just a regulairy 340 5door...or even worse: a 360 (probably not)
Funnily enough, the term "300 Series" or the even more ponderous "340 / 360 Series" never really cought on over here. For those Germans who still remember the little Volvo it'll always be "the 343", no matter whether it's a 345, or a 5-door 340 / 360. Every now and then I hear people mumbling "Mein Gott, a 343, haven't seen one of those in a while" while filling up my '88 360 ...