In general terms, and using solar excess to charge your EV, given this is still an AC supply source it doesn't really matter. As your solar inverter only outputs AC to the house, your charger will be on that side of the supply.
As a preference what you want is to have some intelligence built into the charger that doesn't do lots of small start/stop charges because there is still an element of negotiation between charger and car, electrics have to initialise, etc.
As
@Jomarkh mentioned, units like the MyEnergi Zappi 2 have settings that allow you to define the timer before it kicks in, during which the solar excess to the grid has to stay above a set minimum limit. This helps with things like clouds for a few minutes etc.
It is however important to get the threshold right for your circumstances. Some say a 100W excess for 30 seconds is enough, for others it needs to be more. You'll need to find the sweet spot for you in the 100W to 300W range. Bear in mind these are still small values in electrical terms, so you're not giving away loads of free electricity to the grid.
If you have things like a solar water heater, say the MyEnergi Eddi, you need to take that into account as well in terms of how to manage the use of your excess solar when you have some. Clearly, you have much more across March-September, but much less (indeed maybe none based on your general consumption) across October-February.
But you shouldn't be too concerned with this as car manufacturers do lots of testing of their systems to cover these sorts of situations. As the use of solar has increased in residential properties, so have the cars improved in how they work with intelligent chargers.
And at the end of the day, there is an agreed international standard and protocol/handshake between chargers and EVs, and this is all covered by that standard.
