With all the illegals coming in and a virtually non existent border, I doubt you'll be noticed.
...if you are driving a "plated vehicle" over the US border (not humping it into the USA illegally from Mexico with a backpack), that vehicle (whether you are driving it, or someone else is) will be tracked. My understanding is that there are thousands (or, tens of thousands) of license plate tracking cameras mounted at overpasses, and in towns and cities all across the USA (and, Canada), that record, and plot every license plate that cross the scanner, (potentially) generating a time/date/route event. Again, this I understand from reading professional Geo-spatial journals in my field of endeavor.
...so,if you extrapolate the possible queries made on your vehicle from such an alleged network of national scanners (ie. you tell Customs you are going be in the USA for 21 days to visit in Texas, but you never actually go there, instead, arriving to Los Angeles, and leaving the USA by automobile into Canada in 36 days)..a red flag event....you get the picture.