Lifetime car guy here... Been in the biz since the day I walked out of ole miss in 2003.. you can make a living doing both but I will try to lay out a few pros and cons..
With Benz you will more than like be suit/tie.. you will have to be up to date on product knowledge.. online classes all the time so you can tell a doctor whats the main diff between a C300 and a C350..
With a hyundai dealership it will prolly be khakis/polo and very few classes and such..
Even tho benz's cost alot more the buyers are alot more educated.. and will be shopping 5 states over for the best deal... with hyundai who shops five states over for a hyundai sonata? lol..
And lets be honest.. the money is in the used cars.. So i would look at how many used the MB/hyundai keep.. if the MB keeps 50 and hyundai 150 its a no brainer..
also look at pay plans.. i would try to get at least 25-30% on the front and 5% on the back..
also talk to some of the salesmen.. if the majority of them have been there 5+ years then its a HONEY HOLE and go there.. if they are all less than a year or so then not so much!
Also the main thing in the car biz IS TO GET SOMEWHERE AND STAY SOMEWHERE!!! most people trade every 3-5 years... so after 5 years if you do good followup and good deliveries you will not even have to work the lot.. you will just sell repeats/referrals and let the new guys hustle the lot while you make 100k..
so even if the first yr or two is hard just grind it out and mail/call your clients/customers every 6 months.. they might tell you about a prob but if you handle it you have a customer FOR LIFE!
I dont know the exact situ with the dealerships mentioned and where they are located but I would lean towards the hyundai dealership.. although at mb if you do your time 10+ years you will be 120k+ but those first few will be a bitch bc most mb customers this isnt their first and prolly already have a guy they deal with etc.. so you will have to concentrate on new mb clients etc..
I have sold ford toyota hyundai chevy dodge acura etc.. been at a ford store now for about 2 years and Im not going anywhere.. dealership hopping is never a good idea bc your clients usually dont follow.. i have heard car max has weird pay plans etc.. my worst year was when obama first won in 08 and the banks tightened up and I still made 40k... best year was last year.. i walked out of prison in jan started in april and still made over 60k.. and missed most of tax season which is good bc of down payment money.. would have made 90K if I worked the whole year..
so when you start plan on making a career out of it.. keep track of every sale you make and follow up every 3-6 months with EVERY CUSTOMER!! beat your name in their head and I promise you they will come back and send everyone they know to you as well..
if you have any other ?s shoot me a pm brother..
and like richie said.. if you make 7000 on someone on a used car and they look up the value a few months later they WILL NEVER BE BACK and tell everyone they know how you knocked their head off.. so i try to keep a decent profit and be fair.. i would rather make 2000 on them and every family member for the next 40 years than make 7000 one time and never see them again ,,,,
Taking advantage of someone, rich or poor, is straight up scummy.
Justifying it because they have money doesn't make it ok.
Doing what's best for everyone, no matter their financial situation, will yield greater return in the long run