i dont feel comfortable buying a german car based on our shared history
Because your explanation is terse, and not as explanatory as you may think, I'll assume "shared history' = WWII/Holocaust?
If so, do you (or would you) fly Air France, use BIC pens, or otherwise contribute in any way to supporting the economy in France? (See
Second Crusade.)
Do you (or would you) fly British Airways, drink scotch, or otherwise contribute in any way to supporting the economy of Great Britain? (See
Edict of Expulsion.)
Do you (or would you) fly Iberia Airlines, eat Spanish olives, or otherwise contribute in any way to supporting the economy of Spain? (See
Spanish Inquisition.)
Need I continue, or can you provide a meaningful distinction among and between them and your seemingly incongruent stance on German products? (Aside, of course, for the temporal proximity.)