i sell used cars for a living and if i could give you some advice it would be this:
as far as the interview goes you have to sell yourself because salesman are not hard to find from what i've seen and everyone in that industry is disposable.
the advice i can give you is about the job itself and this might help you with questions in the interview...
make sure you dig deep in your brain and understand this... QUALIFY
QUALIFY
QUALIFY
QUALIFY
by qualifying i mean get to know your customer within minutes...that means find out what car they are looking for, who its for, (and consequently what they need it for), whether they're financing or paying cash and the best one...when are they looking at doing something?...
by doing this you not only don't look like a cockhead to your boss when he asks you these questions (coz he will every single time) but most importantly you don't waste your time coz if they're not gonna buy something on that day then you can move onto a customer who will (unless its quiet and you're not doing anything then you can spend time with time wasters and waste their time too)
make no mistake, if you wanna make money in car sales...learn to qualify as best as you can and don't be afraid of the fuckers (customers) you gotta ask or else you won't be able to put them in a car.
remember, anyone can sell a car to a dummy who walks in and says i want that one.
also another good part about qualifying is that it becomes easier for your boss or manager to "close" the deal for you coz he doesn't have to go through the whole process again only to find out they actually wanted to finance a 15 year old car that costs $4k
as a cadet you have to get the manager involved as soon as you're stuck because they're the ones that will close the deal for you and you get the commission.
and another piece of advice; don't get into new cars, go straight for used cars...thats where the money is and delivery time is almost instant if not a few days at worst which means you get paid quicker.
and don't worry about 40k retainer a year...in used cars you have the ability to make up to $120k a year if you can sell 25 - 30 cars a month...you can sit there and make $60k - $80k a year by selling 10 - 15 cars a month but if you go hard (and its not a hard job apart from the fuckheads who are the boss's in most dealerships) you can easily make 100k a year.
of course the figures i'm giving can vary from dealership to dealership because each one has different payment structures...but if you learn to be a good salesman (i have to mention qualifying again) then you can go to any yard and tell them what to pay you
good luck mate, and i can guarantee you'll have a laugh selling cars with all the 'heads' you meet
if you need any further help, pm me...