Towing a rear-wheel-drive vehicle by the front wheels forces the transmission to rotate backward. This isn't how it's designed to work and will cause significant internal damage, potentially ruining the transmission completely. Even a short distance can cause considerable harm. 400 miles would almost certainly be catastrophic.
Always consult your vehicle's owner's manual for proper towing procedures. For a rear-wheel-drive vehicle, it's generally recommended to tow it on a flatbed or with the rear wheels on the ground (if it's drivable enough). Disconnecting the driveshaft is crucial if towing by the front wheels is absolutely necessary and even then only for very short distances.
