I agree with Larry... but I think the problem is "expectations". Don't expect a classic car or an antique to be like a "modern marvel" and understand that most of us who own these , less than perfect and likely to break down, vehicles are doing the repairs "our selves"... "self tune ups", "self diagnosis", "self DAILY upkeep"... and just a few of the guys out there are able to hire someone else to care for their toys. All that said; understand that part of this process is FRUSTRATION at times and that frustration will lead to selling the classic and purchasing a Chevy, Toyota, Mazda, SUV, or other fake sports vehicle and being happy with a fake. That is fine if that is what works for you... but don't let breakdowns anger you into "never buying a Jaguar again". Jaguar has the 3rd least repairs per hundred vehicles sold in the last 10+ years according to (I think it was) J.D. Powers survey that I read a few months back.
We do the upkeep and we get over the frustration so we can drive a true sports car, a unique vehicle, and one with very special style/class/looks.
I do 90% or more of my own work and sometimes I want to put a match to them; then I look at my driveway and smile: 76MGB, 76MG Midget,78MGB, 79MGB, 94 and 96 Jaguars, 59Nash Metro, 71VW, 77VW,
(& a little Bosch)
Hang in there...keep the Jaguar; but expect some problems.