I haven't had a courtesy car for years, but had a Proton for a few days when my ST24 went in for some work, was bloody horrible. WHen I had my 1st RS Turbo, gearbox went bang after a few weeks, I had a P reg Mondeo Ghia X V6 off the forecourt, went well enough but managed to hit a dog on the A14 and done a fair bit of damage, smashed front bumper, washer bottle, scuffed all 4 wheels....
ANd when I had my Orion I had a load of grief getting some work done under warrenty, ended up getting Ford HQ involved, and when they finally took the car in for some work I had the use of the Sales Managers Escort, that saw some abuse that day....

Finally, a garage I used to work at had a Perodua Nippa for a courtesy car, proper bargain basement, but went well.