If I'm correct, but did you say you imported a new car? That car may be causing the problems. Try replacing it and it'll more than likely resolve your problems :)
Simply reload your scripts when it happens. You can do that by pressing ` or ~ (They're the same thing) and type this in without the quotes, "reloadscripts" That should then solve the problem.
Judging by the photos...I already see a crash coming. When using ELS cars and other mods, there's a huge possibility of the game crashing. Just a heads up, LOL.
I'd replace that vehicle with a different. Just last night I was installing a car mod, (The CHP Crown Vic) and every time I went to pick it, the game crashed. The only way to fix it is to replace the car with a different mod or place the original ones back in.
Actually, there are EMS missions in a separate mod called the Paramedic mod. However, this site's mostly about policing, hence why the title, "Liberty City Police Department First Response."
I don't anyone will make it though given the circumstances because it's really pointless in my opinion since it wouldn't be drive-able and stuff. I do like the idea of this though...someone should make it!