Could it be one of your brakes locking up? It happened on a friends 733i BMW. It drove fine but always squeaked and ate his rotor to bits.
1987 mercedes 300E
1995 e320 conversion(hated the 300e grill)
Monochromatic Paint (Custom Blue)
Flat Badged (front)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS