If the steak tips are long strips, leave them that way. If they are already cut into pieces, that is fine too. Place in a gallon zip lock bag. Mix 1 cup of the BBQ sauce, all of the vinaigrette, the Dr pepper, vinegar and oil and pour over the meat. Marinate for about 12 hours but no longer that 24.
When ready to grill, heat grill to high.
Discard marinade and rinse the beef. Then pat dry, really pressing the paper towels into the meat.
Oil the grill and the tips and place on the grill for two minutes. Flip and brush on the Dr Pepper BBQ sauce. After two minutes flip again and brush on more Dr Pepper BBQ sauce. Continue with this process using about 2 cups of the BBQ sauce or until the tips are cooked to your desired doneness. Save the remaining cup of BBQ sauce for serving.
Remove the tips from the grill and let sit 10 minutes before cutting further and serving.
If you used already cut up tips, serve with the additional BBQ sauce. If you bought the long strips, cut them now into chunks and serve with the BBQ sauce.
Good served with our garlic mashed potatoes, see here.