OTA should in fact be more reliable than the current process having the dealer in the middle who employs humans who can make instakes. OTA will know exactly the set of module/software versions installed on each individual car and can apply the specific module updates appropriately. This will drastically reduce any errors.
OTA is just a means of transport of the total update. For the update to be correct you still need all the controls and a sufficiently automated process to avoid user interaction. They clearly do not have them.
So they rely on the input of the trained mechanic to control the process, and to verify if it is done successfully.
However, if cheap hardware has unstable qualities, even if the update is correct the end effect may be that the car does not function properly.
Updates of modules that are known to induce safety issues or highly influence the basic functioning of the car are the most vulnerable ones. If you cannot be sure that every single update works, you need a mechanic to verify. End of customer OTA.
However, I doubt that a mechanic will test a power curve at higher speeds if the power curve itself hasn't been listed as a root cause for an update...
Normally with so many systems to be updated, you collect all updates, pack them and test them as one very thorougly on all systems they apply to. Then you can update safely.
However, if "the systems" only exist on paper and in fact may have different subversions or subsets with flawed hardware, you are in trouble. Your package will be invalid for an unknown number of cases. So you have make smaller update packages, possibly all the way up to a single hardware module level.
Lower hardware prices induce such variations. If the lower price of hardware help you to reduce the total price for the customer, there is no added margin for the manufacturer to 'solve' the higher number of issues afterwards.
This explains the module based approach for updates on the MG. And it explains why both dealer and MG often seem to have no clue at all what causes what, an why MG cuts aftersales costs when dealing with issues.
and flashed with R33.
