Has any one any experience of using a Master Blaster car dryer vs a similar power (on paper) pet dryer which are many times cheaper.  As I would only use one about 5 or 6 times a year I am looking for a quick - no touch -way to dry my car quickly but do want to spend more than is necessary.

May not be what you're looking for, but I've used one of these for a few years now to blast out trapped water in all the nooks and crannies after rinsing and drying. It does a really good job too. Fabulous for `no touch` drying of the wheels.

 

https://www.christiesdirect.com/en/Metro-Air-Force-Quick-Draw-Mini-Model/m-4488.aspx?gclid=EAIaIQobChMI1r2hpLK_2AIVip3tCh1Pyw0JEAYYASABEgKpEPD_BwE&utm_source=google&utm_medium=shopping&utm_campaign=UnitedKingdom

I don't have any experience with the mater blaster but have used a 2800w pet dryer for a number of years and IMO it's all you need and at under £50 are good value too. As an example of it's power it has on occasion blown the plastic covers off the wheel nut studs on my vRS. Mine has 2 speeds and 2 heat settings (but I have never used the heat as it warms the air anyway) but the switches are on the side of the base and are easily knocked when moving it about so I'd get one with the switches on the top similar to this one 

 

https://www.ebay.co.uk/itm/2800W-Dog-Cat-Pet-Grooming-Hair-Dryer-Hairdryer-Blaster-Low-Noise-Blower-Heater/122509342796?epid=1579348082&hash=item1c8620384c:m:mCXiGmZxKpta7izVzqPerFQ

Pet dryer has proven a real bargain.... although i think prices have gone up a little since;

but i got mine for under £40 and it's now 3 years old and still going strong.

 

Master Blaster setup is nice - with extended hose etc..... but hard to justify the price.