The point may be moot by now but two things in this story are red flags for me:
1) cheap aftermarket rims and 2) car bought from a used car dealer.

The cheesy wheels are a good reflection of how this car was treated and serviced. In this case its confirmed by lack of service records, excessive wear and tear and of course engine problems.

I have yet to see a gem on the non-franchized dealer's lot. I don't mean exotic car specialty houses or late models but the kind of cars we are discussing here. Rule of thumb is to go for the best car you can afford. Low price may be a factor at the time of purchase, but immediately thereafter its the condition that is a key issue.

Smart move by passing on this particular car. Save aggravation by having a car inspected by a certified Jaguar mechanic. Good luck.