Oscar Mayer is offering use of the Wienermobile for many things, "If you have something big planned, the Wienermobile wants to help." Now for marriage proposals. That was inspired by one of their employees using it to propose at Yellowstone.
The cool thing is they are not charging people for use. They do recommend trying to get approval to use it many months in advance. Quite the creative way to have a memorable proposal and also great social exposure for them. UPI