The EFI will run for years with no trouble, then cost you a couple thousand all at once, typically.
Body rust is the other big problem, along with climate control failure ($500 for a new servo box).
I'd not bother impressing at risk teens, they need common sense and good example more than anything else, catering to them is only encouraging bad behavior. Parenting is what saves them, very little else, and that only works when they are young (speaking from experience here....).
By all means, buy it if you want, but it will be a gas hog, and very few kids are impressed by my 280 SE 4.5, which is a much more noticable car than a 450 SE.
Best of luck!
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!