Depends who you are buying from or what you are buying. If from a dealer, no, because a dealer remains liable for any significant faults that could have been present or developing on date of sale for 6 months from date of sale. If buying privately, with no warranty and no such liability, you have to balance the saving against the cost of the inspection that will be £200 - £300. And if the vendor sells the car before the inspection can be carried out you will still be liable for a cancellation fee.